English
Quantum materials is a general term in condensed matter physics that includes all materials whose essential properties requires advanced quantum mechanics to explain. There is a wide variety of phenomena involving quantum materials, including, but not limited to, superconductivity, topological phases of matter, quantum optics, quantum computing, spintronics, etc. Many of these phenomena arise from dimensional reduction, interactions between constituent particles, or the specific geometry of electronic structures. The phenomena and properties of these materials have been the subject of active studies worldwide to investigate their physical mechanisms and explore their potential applications in electronics and information technology.
Within Indonesia, it is realized that participating in research on quantum materials is important for the future development of our country. However, the research interest in this field has been growing in only a small theoretical physics community. Hence, promoting this research field to a broader scientific community is essential. This motivates us to propose a mini-school on quantum materials to raise awareness of the current research progress and introduce to our scientific community the relevant knowledge and tools needed to perform research in this field through lectures and hands-on training. The purpose of this Asian Network Mini-School on Quantum Materials 2024 (ANMSQM-2024) is to allow scientists, especially early career researchers and graduate students in Indonesia and the neighboring Southeast Asian countries as members of the network, to interact with and gain advanced knowledge from experts in the related fields from ICTP, APCTP, PCS-IBS, and other institutes. This mini-school also encourages active interaction between invited lecturers, academics, researchers, and graduate students to share their work and ideas, get information regarding current research trends, and initiate possible collaborations.
This meeting is part of a series of events (https://pcs.ibs.re.kr/ICTP_Asian_Network/ICTP_Events.html) held by our ICTP Asian Network (https://pcs.ibs.re.kr/ICTP_Asian_Network/ICTP_Asian_Network.html ). In particular, our Network is planning Mini-Schools in each year of the three years 2023, 2024 and 2025. This event follows on from the successful Network Mini-School on Quantum Computing and Simulation held from 6-8 December 2023 at BRIN, Serpong Indonesia. It will be followed up by a more advanced Network Mini-Workshop on Magnetism and Spectroscopy to be held from 16-17 November 2024 at SUT, Nakhon Ratchasima, Thailand.
No. | Name | Affiliation | Position |
1 | Paul Pearce | Univ. of Melbourne and APCTP | Advisory Committee |
2 | A. Agung Nugroho | Institut Teknologi Bandung (ITB) | Advisory Committee / Lecturer |
3 | M. Aziz Majidi | Universitas Indonesia (UI) | Chair / Lecturer |
4 | Ahmad Ridwan Tresna Nugraha | Research Center for Quantum Physics (PRFK-BRIN) | Co-Chair / Lecturer |
5 | Adam Badra Cahaya | Universitas Indonesia (UI) | Organizer / Lecturer |
6 | M. Adhib Ulil Absor | Universitas Gajah Mada (UGM) | Lecturer |
7 | Ar Rohim | Universitas Indonesia (UI) | Organizer |
8 | Anjar Taufik Hidayat | Universitas Indonesia (UI) | Organizer |
9 | Seno Aji | Universitas Indonesia (UI) | Organizer |
10 | Ferry Anggoro Ardy Nugroho | Universitas Indonesia (UI) | Organizer |
11 | Januar Widakdo | Universitas Indonesia (UI) | Organizer |
12 | Syahril Siregar | Universitas Indonesia (UI) | Organizer |
No. | Name | Affiliation |
1 | Han Woong Yeom | Pohang University of Technology (POSTECH), Korea |
2 | Daniel Leykam | Singapore University of Technology and Design, Singapore |
3 | Koichi Kusakabe | University of Hyogo, Japan |
4 | Jung-Wan Ryu | Center for Theoretical Physics of Complex Systems – Institute for Basic Science (PCS-IBS), Korea |
Venue
Auditorium Prof. Dr. Soemantri Brodjonegoro, Building B, Faculty of Mathematics and Natural Sciences (FMIPA UI)
Program Structure
The school lectures will be of pedagogical nature and offer an introductory level suited to advanced undergraduate and graduate students in physics and materials science. These students are in the stage of doing their dissertation, theses, or final projects in the fields of condensed matter physics, materials science and complex systems. Other participants include postdoctoral fellows, or those who obtained their Ph.D. degrees within five years prior to the school, as well as early career researchers. This activity is open to participants from all APCTP Member Countries and ICTP OEA regional countries on the UNESCO list, with the primary target audience being scientists and students residing in Indonesia.
The Mini-School program consists of lectures suited for advanced students and is given by invited scientists who are active practitioners in their research fields. Some lecturers will provide two (2) continuing one-hour lectures, while others will give one-hour lectures. The first few lectures will be at an introductory level. They will cover the physical concepts of topological phases of matter, spintronics, and other phenomena of quantum materials, the experimental findings that reveal them, and the current research progress in the related fields. The following lectures will address how research in this field is approached theoretically through first principles techniques and modelings. The last few lectures will be provided for hands-on training on several software packages relevant to research in this field. The second half of the last day of the mini-school will be designated for poster sessions. The poster sessions will exhibit the current research work of participants in theoretical and experimental condensed matter physics and materials science. To encourage discussion among invited lecturers and speakers, researchers, and students, there will be sufficient time allotted for open forums and coffee breaks after each lecture and during the poster session.
|
Time |
Monday Sept 2, 2024 |
Tuesday Sept 3, 2024 |
Wednesday Sept 4, 2024 |
|
07.45 – 08.30 |
Registration |
|
|
|
08.30 – 09.00 |
Opening Session |
Registration |
Registration |
|
09.00 – 09.15 |
Lecture 5 (part 1): Koichi Kusakabe Charge and Spin Transport in Heterostructure Systems |
Lecture 8 (part 1): Ahmad Ridwan Tresna Nugraha Quantum ESPRESSO and Wannier90 Crash Course |
|
|
09.15 – 10.00 |
Lecture 1 (part 1): Han Woong Yeom Topological Excitations in Van der Waals Materials |
||
|
10.00 – 10.15 |
Coffee Break |
Coffee Break |
|
|
10.15 – 10.30 |
Coffee Break |
||
|
10.30 – 11.30 |
Lecture 1 (part 2): Han Woong Yeom Topological Excitations in Van der Waals Materials |
Lecture 5 (part 2): Koichi Kusakabe Charge and Spin Transport in Heterostructure Systems |
Lecture 8 (part 2): Ahmad Ridwan Tresna Nugraha Quantum ESPRESSO and Wannier90 Crash Course |
|
11.30 – 13.00 |
Lunch |
Lunch |
Lunch |
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13.00 – 14.00 |
Lecture 2 (part 1): Daniel Leykam Exploring Topological Properties of Materials through Photonics |
Poster Session |
Lecture 9 (part 1): Muhammad Aziz Majidi Tutorial on Tight-Binding Model and Green Functions |
|
14.00 – 14.15 |
Coffee Break |
Coffee Break |
Coffee Break |
|
14.15 – 15.15 |
Lecture 2 (part 2): Daniel Leykam Exploring Topological Properties of Materials through Photonics |
Lecture 6 (part 1): Jung-Wan Ryu Topological Structures of Energy Bands in Non-Hermitian Systems |
Lecture 9 (part 2): Muhammad Aziz Majidi Tutorial on Tight-Binding Model and Green Functions |
|
15.15 – 15.30 |
Coffee Break |
Coffee Break |
Coffee Break |
|
15.30 – 16.30 |
Lecture 3: A Agung Nugroho Synthesis and Characterization of Topological Materials |
Lecture 6 (part 2): Jung-Wan Ryu Topological Structures of Energy Bands in Non-Hermitian Systems |
Closing Session |
|
16.30 – 16.45 |
Coffee Break |
Coffee Break |
|
|
16.45 – 17.45 |
Lecture 4: Adam Badra Cahaya Spin Pumping and Spin-Orbit Torque |
Lecture 7: Moh. Adhib Ulil Absor Development of persistent spin-textured materials for dissipationless spintronics |
|
Abstracts
1 Center for Artificial Low-Dimensional Electronic Systems, Institute for Basic Science
2 Professor at Department of Physics, POSTECH
Email: yeom [at] postech.ac.kr
Topological excitations or domain walls (DWs) are ubiquitous in magnetic, ferroelectric, multiferroic, and charge density wave (CDW) materials with critical roles in a variety of emerging physics and functionality. The fundamental understanding of DWs in CDW systems is based on the concept of topological solitons 1D CDW systems, which have been microscopically characterized in recent years [1, 2]. However, the atomic structure and electronic states of DWs in 2D CDW systems have not been sufficiently clear. In this talk, we will review our recent research activity for atomic scale observation and manipulation of DW topological excitations in prototypical 2D CDW systems with strong many-body interactions. Domain walls of the unique Mott-CDW insulating states of 1T-TaS2 are investigated in great detail [3-5], which have been related to emerging superconductivity and memristic switching behavior. We will first introduce atomic and electronic structures of a variety of DWs in this system, which include distinct electronic states within the Mott gap. The in-gap states are largely determined by strong electron correlation and structural reconstructions, indicating the multiple internal degrees of freedom within DWs [4]. A network of such DWs is also formed and hosts novel electronic states, which are related to the emergence of flat bands and superconductivity [5]. In another prototypical 2D CDW of 2H-NbSe2, the CDW ground state has been known as being incommensurate, but the DWs for the incommensuration had not been identified. An unusual DW structure is introduced in this system, which is formed by the competition of two distinct CDW structures [6]. For the other prototypical CDW system of TiSe2, we for the first time clarified DWs connecting chiral CDW domains. These chiral DWs do not exhibit any in-gap states, defying the general concept of a CDW DW and denying its role in emerging superconductivity [7]. All these results converge to tell us the rich physics within topological excitations through the intricate interplay of diverse interactions, which in turn indicates the possibility of manipulating exotic quantum states through topological excitations in 1D/2D systems.
- [1] S. M. Cheon, S.-H. Lee, T.-H. Kim and H. W. Yeom, Science 350 (2015), 6257.
- T J. W. Park, E. Do, J. S. Shin, S. K. Song, O. Stetsovych, P. Jelinek, and H. W. Yeom, Nature Nanotechnology 17, 244 (2022).
- D. Cho et al., Nat. Commun. 7 (2016), 10453.
- D. Cho et al., Nat. Commun. 8 (2017), 392.
- J. H. Park, G. Y. Cho, D. Cho, and H. W. Yeom, Nat. Commun. 10, 4038 (2019).
- G. Gye, E. Oh, and H. W. Yeom, Phys. Rev. Lett. 122, 016403 (2019).
- H. J. Kim, K.-H. Jin, and H. W. Yeom, submitted (2024).
Researcher at Science, Mathematics and Technology Cluster, Singapore University of Technology and Design
Email: daniel.leykam [at] gmail.com
There is a great deal of ongoing interest in topological materials including graphene, topological insulators, and Weyl semimetals. These are condensed matter systems with novel electronic properties such as disorder-robust conducting edge states that are protected by the abstract mathematics of topology. Photonics provides a highly flexible platform for emulating and better understanding these exotic materials. First, I will survey methods for emulating the single particle Hamiltonians describing various quantum materials using light propagation in coupled cavities and waveguide arrays. Next, I will discuss exciting recent progress towards the photonic emulation of strongly-correlated quantum materials. Finally, I will show how suitably-tailored optical nonlinearities or losses can be used to achieve a controlled “filling” of photonic bands, mimicking electronic topological insulators.
1 Professor at Intitut Teknologi Bandung, Bandung, Indonesia
Email: a.a.nugroho [at] itb.ac.id
Topological material is a class of material that has topological character in its electronic band structure. The topological character was first recognized in quantum hall phenomena and further in spin hall phenomena to topological insulator and band crossing. Both theoretical support and experimental evidence accelerate the exploration to functionalize the topological materials. For the experiment to realize the theoretical suggestions or the theory to explain the experimental findings for the topological material, the measured physical properties should be measured in a well-defined crystallinity and stoichiometric sample. In this lecture, the preparation of the single-crystalline topological materials and its characterizations will be presented. The journey to obtain a colossal anomalous Nernst of magnetic topological material, Co2MaGa, will be described.
Assistant Professor, Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424, INDONESIA
Email: adam [at] sci.ui.ac.id
In recent years, spintronics, or spin electronics, has emerged as a pivotal field in condensed matter physics, offering transformative potential for future electronic devices through the manipulation of electron spin rather than charge. This talk presents a lecture on the cutting-edge phenomena of spin pumping and spin-orbit torque (SOT), which are pivotal to the evolving field of spintronics. This lecture will provide a comprehensive overview of the theoretical foundations and experimental breakthroughs that have propelled these phenomena to the forefront of condensed matter physics research. Spin pumping serves as a fundamental mechanism for generating pure spin currents. Spin pumping involves the transfer of angular momentum from a precessing magnetization in a ferromagnetic material to an adjacent non-magnetic layer in form of a pure spin current. This mechanism is instrumental in a variety of spintronic applications, including enhanced magnetic damping and spin current generation, which are essential for the development of next-generation electronic devices [1].
Spin-orbit torque, on the other hand, emerges from the coupling between the spin and orbital degrees of freedom in materials with strong spin-orbit interaction. This effect enables the manipulation of magnetic states through electrical currents, offering a highly efficient pathway for magnetic switching. The ability to control magnetization dynamically and with low power consumption makes spin-orbit torque a cornerstone for advancements in non-volatile memory technologies and other spintronic applications [2]. This talk discusses the theoretical models that describe spin pumping and spin-orbit torque, as well as recent research developments and the practical implications of these phenomena in the context of modern spintronic devices.
- A.B. Cahaya, A. O., Leon, & G.E.W. Bauer (2017). Crystal field effects on spin pumping. Physical Review B, 96(14), 144434..
- A.B. Cahaya, A. O. Leon, & M.H. Fauzi (2023). Spin–orbit torque on nuclear spins exerted by a spin accumulation via hyperfine interactions. Nanotechnology, 34(50), 505001.
Professor, University of Hyogo, Japan
Email: kusakabe [at] sci.u-hyogo.ac.jp
Materials with potential applications for spintronics and quantum information processing include stacked atomic layers. In particular, typical materials such as graphene and hexagonal BN have an advantage that, in their crystalline form, the materials themselves have no local magnetic moment. We have shown that, in graphene and BN, even strong magnetism can be realized by modifying the atomic-scale material structure. We will present several examples of our research, including ongoing collaborations between Japan and Indonesia. [1-6] In particular, these systems exhibit the designed metal-insulator transition, artificially realized magnetic ordering, strongly correlated quantum effects, entangled spin states, etc. in the designed heterostructures. As a result, our research suggests that we can theoretically propose structures that can surpass the spin conduction and quantum information processing that have already been realized. In the first part of this lecture, examples of heterostructures that can be applied to spintronics and quantum information processing are presented. The second part outlines electronic structure calculation methods used in our theoretical design.
- Harfah, Y. Wicaksono, G. K. Sunnardianto, M. A. Majidi, and K. Kusakabe, “Ultra-thin van der Waals magnetic tunnel junction based on monoatomic boron vacancy of hexagonal boron nitride”, Phys. Chem. Chem. Phys., 26, 9733 (2024).
- Wicaksono, H. Harfah, G. K. Sunnardianto, M. A. Majidi, and K. Kusakabe, “Colossal In-plane Magnetoresistance Ratio of Graphene Sandwiched with Ni Nanostructures”, RSC Adv., 12, 13985 (2022).
- Morishita, Y. Oishi, T. Yamaguchi, K. Kusakabe, “S=1 antiferromagnetic electron-spin systems on hydrogenated phenalenyl-tessellation molecules for material-based quantum-computation resources”, Appl. Phys. Express, 14, 121005 (2021).
- Harfah, Y. Wicaksono, M.A. Majidi, and K. Kusakabe, “Spin-current control by induced electric-polarization reversal in Ni/hBN/Ni: A cross-correlation material”, ACS Appl. Elec. Materials, 2, 1689 (2020).
- Wicaksono, S. Teranishi, K. Nishiguchi, K. Kusakabe, “Tunable induced magnetic moment and in-planeconductance of graphene in Ni/Graphene/Ni nano spin-valve like structure: a first principles study”, CARBON, 143, 828 (2019).
- Kusakabe and M. Maruyama, “Magnetic nanographite”, Phys. Rev. B, 67 (2003) 092406.
Researcher at Center of Theoretical Physics of Complex Systems – Institute of Basic Science, Daejeon, Korea
Email: jungwanryu [at] ibs.re.kr, jungwanryu [at] gmail.com
Non-hermiticity, which describes open systems with energy gain and loss, is ubiquitous in many branches of physics, such as quantum mechanics, optics, condensed matter physics, and nonlinear dynamics. In non-Hermitian systems, eigenvalues can be complex, and eigenstates can be non-orthogonal, leading to rich and novel physical phenomena not present in Hermitian systems. The topology in non-Hermitian systems arises from these intrinsic properties, in addition to the traditional Hermitian topology derived from Berry phases of eigenstates. This lecture will discuss complex eigenvalues and non-orthogonal eigenstates, the point gap of complex energy bands, exceptional points, and their topological properties in non-Hermitian systems. We will explore these phenomena in detail, examining how non-Hermitian systems extend our understanding of the topological structure of energy bands and open up new avenues for research and applications. The theoretical framework and experimental realizations of these unique topological features in various physical systems will also be discussed.
Associate Professor, Department of Physics, Faculty of Mathematics and Natural Sciences,
Gadjah Mada University, Yogyakarta, INDONESIA
Email: adib [at] ugm.ac.id
Spin-orbit coupling (SOC), which links the spin degree of freedom with the orbital motion of electrons in crystalline solids, is crucial for the development of new physical phenomena. In non-centrosymmetric materials, SOC aligns the electron’s spin direction with its momentum, resulting in complex spin textures in reciprocal k-space. Depending on the crystal symmetry, these spin textures can manifest as Rashba, Dresselhaus, persistent, or more complex configurations. In this talk, we will present our recent findings on spin-textured physics in 2D-related materials [1-8] and discuss their potential implications for spintronic applications. Specifically, we have delved into the emergence of persistent spin textures, a characteristic of certain materials that allows them to maintain a consistent spin configuration in momentum space. This feature is predicted to result in an exceptionally long spin lifetime for carriers, which is promising for dissipationless spintronics devices.
Keywords: Spintronics, spin textures, spin-orbit coupling.
- Absor, M.A.U, Santoso I, and Harsojo, Phys. Rev. B 109, 115141 (2024).
- Umar, M.D., Falihin, L.D. , Lukmantoro, A. , Harsojo, Absor, M.A.U., Phys. Rev. B 108, 035109 (2023).
- Lukmantoro A., Absor, M.A.U., Phys. Rev. Materials 7, 104005 (2023).
- Absor, M.A.U. , Lukmantoro A. , Santoso I., J. Phys. Cond. Matter 34, 445501 (2022).
- Absor, M.A.U., I Santoso, J. Appl. Phys. 132, 183906 (2022).
- Sasmito, S.A., Anshory, M., Jihad, I., Absor, M.A.U., Phys. Rev. B 104, 115145 (2021).
- Absor, M.A.U., and F. Ishii, Phys. Rev. B 103, 045119 (2021).
- Absor, M.A.U., and F. Ishii, Phys. Rev. B 100, 115104 (2019).
Researcher at Research Center for Quantum Physics – National Research and Innovation Agency, INDONESIA
Email: ahma080 [at] brin.go.id
Quantum ESPRESSO is a suite of open-source codes for materials modeling and simulation, while Wannier90 is an additional tool designed for obtaining maximally-localized Wannier functions, which are crucial for some applications such as electronic structure analysis and transport properties. This tutorial talk is not intended to teach the participants for understanding all features or aspects of Quantum ESPRESSO and Wannier90, yet we hope that we can offer an accessible introduction to those two valuable computational tools in quantum and condensed matter physics. The tutorial will cover the basic principles, installation steps, key features, and practical examples of both Quantum ESPRESSO and Wannier90, providing participants with the foundational knowledge needed to start using these tools in their research.
Associate Professor,
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424, INDONESIA
Email: aziz.majidi [at] sci.ui.ac.id
The tight-binding model, or method, has become a standard tool for constructing a Hamiltonian for a condensed-matter system using atomic orbitals or Wannier functions as its basis set. Its superiority lies in its simple structure, providing flexibility for use as a toy model to reveal a particular physical phenomenon on a qualitative level or to construct a realistic model in which the detailed crystal structure of the system and some form of interaction, such as spin-orbit coupling, need to be incorporated appropriately. Meanwhile, the Green function technique derived from Quantum Field Theory (QFT) is another powerful tool for calculating various physical quantities in condensed-matter systems based on the constructed Hamiltonian. In this lecture, I will review the concept of the tight-binding model and the procedure to build it from the Density Functional Theory (DFT) calculation results. Further, I will go through an example of capturing the surface states of a topological insulator using the Green function technique based on the constructed tight-binding Hamiltonian.
Lecture 1
HAN WOONG YEOM1,2
1 Center for Artificial Low-Dimensional Electronic Systems, Institute for Basic Science
2 Professor at Department of Physics, POSTECH
Email: yeom@postech.ac.kr
Topological excitations in van der Waals materials
Topological excitations or domain walls (DWs) are ubiquitous in magnetic, ferroelectric, multiferroic, and charge density wave (CDW) materials with critical roles in a variety of emerging physics and functionality. The fundamental understanding of DWs in CDW systems is based on the concept of topological solitons 1D CDW systems, which have been microscopically characterized in recent years [1, 2]. However, the atomic structure and electronic states of DWs in 2D CDW systems have not been sufficiently clear. In this talk, we will review our recent research activity for atomic scale observation and manipulation of DW topological excitations in prototypical 2D CDW systems with strong many-body interactions. Domain walls of the unique Mott-CDW insulating states of 1T-TaS2 are investigated in great detail [3-5], which have been related to emerging superconductivity and memristic switching behavior. We will first introduce atomic and electronic structures of a variety of DWs in this system, which include distinct electronic states within the Mott gap. The in-gap states are largely determined by strong electron correlation and structural reconstructions, indicating the multiple internal degrees of freedom within DWs [4]. A network of such DWs is also formed and hosts novel electronic states, which are related to the emergence of flat bands and superconductivity [5]. In another prototypical 2D CDW of 2H-NbSe2, the CDW ground state has been known as being incommensurate, but the DWs for the incommensuration had not been identified. An unusual DW structure is introduced in this system, which is formed by the competition of two distinct CDW structures [6]. For the other prototypical CDW system of TiSe2, we for the first time clarified DWs connecting chiral CDW domains. These chiral DWs do not exhibit any in-gap states, defying the general concept of a CDW DW and denying its role in emerging superconductivity [7]. All these results converge to tell us the rich physics within topological excitations through the intricate interplay of diverse interactions, which in turn indicates the possibility of manipulating exotic quantum states through topological excitations in 1D/2D systems.
- [1] S. M. Cheon, S.-H. Lee, T.-H. Kim and H. W. Yeom, Science 350 (2015), 6257.
- T J. W. Park, E. Do, J. S. Shin, S. K. Song, O. Stetsovych, P. Jelinek, and H. W. Yeom, Nature Nanotechnology 17, 244 (2022).
- D. Cho et al., Nat. Commun. 7 (2016), 10453.
- D. Cho et al., Nat. Commun. 8 (2017), 392.
- J. H. Park, G. Y. Cho, D. Cho, and H. W. Yeom, Nat. Commun. 10, 4038 (2019).
- G. Gye, E. Oh, and H. W. Yeom, Phys. Rev. Lett. 122, 016403 (2019).
- H. J. Kim, K.-H. Jin, and H. W. Yeom, submitted (2024).
Lecture 2
DO VAN NAM
1 Associate Professor at Phenikaa University, Hanoi, Vietnam
Topological Electronics of 2D Materials
Lecture 3
ADAM BADRA CAHAYA
Assistant Professor, Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424, INDONESIA
Email: adam@sci.ui.ac.id
Spin Pumping and Spin-Orbit Torque
In recent years, spintronics, or spin electronics, has emerged as a pivotal field in condensed matter physics, offering transformative potential for future electronic devices through the manipulation of electron spin rather than charge. This talk presents a lecture on the cutting-edge phenomena of spin pumping and spin-orbit torque (SOT), which are pivotal to the evolving field of spintronics. This lecture will provide a comprehensive overview of the theoretical foundations and experimental breakthroughs that have propelled these phenomena to the forefront of condensed matter physics research. Spin pumping serves as a fundamental mechanism for generating pure spin currents. Spin pumping involves the transfer of angular momentum from a precessing magnetization in a ferromagnetic material to an adjacent non-magnetic layer in form of a pure spin current. This mechanism is instrumental in a variety of spintronic applications, including enhanced magnetic damping and spin current generation, which are essential for the development of next-generation electronic devices [1].
Spin-orbit torque, on the other hand, emerges from the coupling between the spin and orbital degrees of freedom in materials with strong spin-orbit interaction. This effect enables the manipulation of magnetic states through electrical currents, offering a highly efficient pathway for magnetic switching. The ability to control magnetization dynamically and with low power consumption makes spin-orbit torque a cornerstone for advancements in non-volatile memory technologies and other spintronic applications [2]. This talk discusses the theoretical models that describe spin pumping and spin-orbit torque, as well as recent research developments and the practical implications of these phenomena in the context of modern spintronic devices.
- A.B. Cahaya, A. O., Leon, & G.E.W. Bauer (2017). Crystal field effects on spin pumping. Physical Review B, 96(14), 144434..
- A.B. Cahaya, A. O. Leon, & M.H. Fauzi (2023). Spin–orbit torque on nuclear spins exerted by a spin accumulation via hyperfine interactions. Nanotechnology, 34(50), 505001.
Charge and Spin Transport in Heterostructure Systems
Materials with potential applications for spintronics and quantum information processing include stacked atomic layers. In particular, typical materials such as graphene and hexagonal BN have an advantage that, in their crystalline form, the materials themselves have no local magnetic moment. We have shown that, in graphene and BN, even strong magnetism can be realized by modifying the atomic-scale material structure. We will present several examples of our research, including ongoing collaborations between Japan and Indonesia. [1-6] In particular, these systems exhibit the designed metal-insulator transition, artificially realized magnetic ordering, strongly correlated quantum effects, entangled spin states, etc. in the designed heterostructures. As a result, our research suggests that we can theoretically propose structures that can surpass the spin conduction and quantum information processing that have already been realized. In the first part of this lecture, examples of heterostructures that can be applied to spintronics and quantum information processing are presented. The second part outlines electronic structure calculation methods used in our theoretical design.
- Harfah, Y. Wicaksono, G. K. Sunnardianto, M. A. Majidi, and K. Kusakabe, “Ultra-thin van der Waals magnetic tunnel junction based on monoatomic boron vacancy of hexagonal boron nitride”, Phys. Chem. Chem. Phys., 26, 9733 (2024).
- Wicaksono, H. Harfah, G. K. Sunnardianto, M. A. Majidi, and K. Kusakabe, “Colossal In-plane Magnetoresistance Ratio of Graphene Sandwiched with Ni Nanostructures”, RSC Adv., 12, 13985 (2022).
- Morishita, Y. Oishi, T. Yamaguchi, K. Kusakabe, “S=1 antiferromagnetic electron-spin systems on hydrogenated phenalenyl-tessellation molecules for material-based quantum-computation resources”, Appl. Phys. Express, 14, 121005 (2021).
- Harfah, Y. Wicaksono, M.A. Majidi, and K. Kusakabe, “Spin-current control by induced electric-polarization reversal in Ni/hBN/Ni: A cross-correlation material”, ACS Appl. Elec. Materials, 2, 1689 (2020).
- Wicaksono, S. Teranishi, K. Nishiguchi, K. Kusakabe, “Tunable induced magnetic moment and in-planeconductance of graphene in Ni/Graphene/Ni nano spin-valve like structure: a first principles study”, CARBON, 143, 828 (2019).
- Kusakabe and M. Maruyama, “Magnetic nanographite”, Phys. Rev. B, 67 (2003) 092406.
Lecture 5
DANIEL LEYKAM
Researcher at Science, Mathematics and Technology Cluster, Singapore University of Technology and Design
Email: daniel.leykam@gmail.com
Exploring topological properties of materials through photonics
There is a great deal of ongoing interest in topological materials including graphene, topological insulators, and Weyl semimetals. These are condensed matter systems with novel electronic properties such as disorder-robust conducting edge states that are protected by the abstract mathematics of topology. Photonics provides a highly flexible platform for emulating and better understanding these exotic materials. First, I will survey methods for emulating the single particle Hamiltonians describing various quantum materials using light propagation in coupled cavities and waveguide arrays. Next, I will discuss exciting recent progress towards the photonic emulation of strongly-correlated quantum materials. Finally, I will show how suitably-tailored optical nonlinearities or losses can be used to achieve a controlled “filling” of photonic bands, mimicking electronic topological insulators.
Lecture 6
MOH. ADHIB ULIL ABSOR
Associate Professor, Department of Physics, Faculty of Mathematics and Natural Sciences,
Gadjah Mada University, Yogyakarta, INDONESIA
Email: adib@ugm.ac.id
Development of persistent spin-textured materials for dissipationless spintronics
Spin-orbit coupling (SOC), which links the spin degree of freedom with the orbital motion of electrons in crystalline solids, is crucial for the development of new physical phenomena. In non-centrosymmetric materials, SOC aligns the electron’s spin direction with its momentum, resulting in complex spin textures in reciprocal k-space. Depending on the crystal symmetry, these spin textures can manifest as Rashba, Dresselhaus, persistent, or more complex configurations. In this talk, we will present our recent findings on spin-textured physics in 2D-related materials [1-8] and discuss their potential implications for spintronic applications. Specifically, we have delved into the emergence of persistent spin textures, a characteristic of certain materials that allows them to maintain a consistent spin configuration in momentum space. This feature is predicted to result in an exceptionally long spin lifetime for carriers, which is promising for dissipationless spintronics devices.
Keywords: Spintronics, spin textures, spin-orbit coupling.
- Absor, M.A.U, Santoso I, and Harsojo, Phys. Rev. B 109, 115141 (2024).
- Umar, M.D., Falihin, L.D. , Lukmantoro, A. , Harsojo, Absor, M.A.U., Phys. Rev. B 108, 035109 (2023).
- Lukmantoro A., Absor, M.A.U., Phys. Rev. Materials 7, 104005 (2023).
- Absor, M.A.U. , Lukmantoro A. , Santoso I., J. Phys. Cond. Matter 34, 445501 (2022).
- Absor, M.A.U., I Santoso, J. Appl. Phys. 132, 183906 (2022).
- Sasmito, S.A., Anshory, M., Jihad, I., Absor, M.A.U., Phys. Rev. B 104, 115145 (2021).
- Absor, M.A.U., and F. Ishii, Phys. Rev. B 103, 045119 (2021).
- Absor, M.A.U., and F. Ishii, Phys. Rev. B 100, 115104 (2019).
Lecture 7
JUNG-WAN RYU
Researcher at Center of Theoretical Physics of Complex Systems – Institute of Basic Science, Daejeon, Korea
Topological Structures of Energy Bands in Non-Hermitian Systems
Non-hermiticity, which describes open systems with energy gain and loss, is ubiquitous in many branches of physics, such as quantum mechanics, optics, condensed matter physics, and nonlinear dynamics. In non-Hermitian systems, eigenvalues can be complex, and eigenstates can be non-orthogonal, leading to rich and novel physical phenomena not present in Hermitian systems. The topology in non-Hermitian systems arises from these intrinsic properties, in addition to the traditional Hermitian topology derived from Berry phases of eigenstates. This lecture will discuss complex eigenvalues and non-orthogonal eigenstates, the point gap of complex energy bands, exceptional points, and their topological properties in non-Hermitian systems. We will explore these phenomena in detail, examining how non-Hermitian systems extend our understanding of the topological structure of energy bands and open up new avenues for research and applications. The theoretical framework and experimental realizations of these unique topological features in various physical systems will also be discussed.
Lecture 8
MUHAMMAD AZIZ MAJIDI
Associate Professor,
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424, INDONESIA
Email: aziz.majidi@sci.ui.ac.id
Tutorial on Tight-Binding Model and Green Function
The tight-binding model, or method, has become a standard tool for constructing a Hamiltonian for a condensed-matter system using atomic orbitals or Wannier functions as its basis set. Its superiority lies in its simple structure, providing flexibility for use as a toy model to reveal a particular physical phenomenon on a qualitative level or to construct a realistic model in which the detailed crystal structure of the system and some form of interaction, such as spin-orbit coupling, need to be incorporated appropriately. Meanwhile, the Green function technique derived from Quantum Field Theory (QFT) is another powerful tool for calculating various physical quantities in condensed-matter systems based on the constructed Hamiltonian. In this lecture, I will review the concept of the tight-binding model and the procedure to build it from the Density Functional Theory (DFT) calculation results. Further, I will go through an example of capturing the surface states of a topological insulator using the Green function technique based on the constructed tight-binding Hamiltonian.
Lecture 9
AHMAD RIDWAN TRESNA NUGRAHA
Researcher at Research Center for Quantum Physics – National Research and Innovation Agency, INDONESIA
Email: ahma080@brin.go.id
Quantum ESPRESSO and Wannier90 Crash Course
Quantum ESPRESSO is a suite of open-source codes for materials modeling and simulation, while Wannier90 is an additional tool designed for obtaining maximally-localized Wannier functions, which are crucial for some applications such as electronic structure analysis and transport properties. This tutorial talk is not intended to teach the participants for understanding all features or aspects of Quantum ESPRESSO and Wannier90, yet we hope that we can offer an accessible introduction to those two valuable computational tools in quantum and condensed matter physics. The tutorial will cover the basic principles, installation steps, key features, and practical examples of both Quantum ESPRESSO and Wannier90, providing participants with the foundational knowledge needed to start using these tools in their research.
List of Participants
|
No. |
Name |
Affiliation |
Status |
|
1 |
Setiya Rahayu |
Institut Teknologi Bandung (ITB) |
Doctorate Student |
|
2 |
Ansell Alvarez Anderson |
Universitas Indonesia (UI) |
Master Student |
|
3 |
Hendry |
Universitas Indonesia (UI) |
Undergraduate Student |
|
4 |
Melinda BR Ginting |
Telkom university |
Faculty |
|
5 |
Haris Suhendar |
Universitas Negeri Jakarta (UNJ) |
Faculty |
|
6 |
Teguh Budi Prayitno |
Universitas Negeri Jakarta (UNJ) |
Faculty |
|
7 |
Paul Ravi Siregar |
Universitas Indonesia (UI) |
Undergraduate Student |
|
8 |
Rukhshon Muhammad Fairuz Abadiy |
IPB University |
Undergraduate Student |
|
9 |
M. ‘Anin Nabail ‘Azhiim |
Universitas Indonesia (UI) |
Undergraduate Student |
|
10 |
Muchamad Fath Bahrul Ulum |
IPB University |
Undergraduate Student |
|
11 |
Cindy Agnitya Pramudita |
Universitas Indonesia (UI) |
Master Student |
|
12 |
Muhammad Yusrul Hanna |
Research Center for Quantum Physics (PRFK-BRIN) |
Junior Researcher |
|
13 |
Muhammad Ahyad |
IPB University |
Master Student |
|
14 |
Kuncoro Nugroho Sakti Muhyi Mustafa |
Universitas Indonesia (UI) |
Undergraduate Student |
|
15 |
Fernando Chandra |
Universitas Indonesia (UI) |
Undergraduate Student |
|
16 |
Muhamad Rafli Gunawan |
Universitas Indonesia (UI) |
Undergraduate Student |
|
17 |
Najwa Zahrani Putria Vairus |
Universitas Indonesia (UI) |
Undergraduate Student |
|
18 |
Fina Fitratun Amaliyah |
UIN Sultan Maulana Hasanuddin Banten |
Master Student |
|
19 |
Mufti Labib Ahmada |
Universitas Pertahanan RI |
Undergraduate Student |
|
20 |
David Graciano |
IPB University |
Undergraduate Student |
|
21 |
Alfian Herdiyanto |
IPB University |
Undergraduate Student |
|
22 |
Antinah |
State University of Jakarta (UNJ) |
Undergraduate Student |
|
23 |
Rian Pratama |
MAS Jamiyyah Islamiyyah |
Faculty |
|
24 |
Nadya Nurul Fatika |
IPB University |
Undergraduate Student |
|
25 |
Siti Khoriah |
IPB University |
Undergraduate Student |
|
26 |
Ariiq Islam Alfajri |
IPB University |
Undergraduate Student |
|
27 |
Hoerudin Bayu Hidayah |
Universitas Indonesia (UI) |
Master student |
|
28 |
Radityo Wisesa |
Universitas Islam Negeri Syarif Hidayatullah Jakarta |
Undergraduate Student |
|
29 |
Pipit Suryani |
IPB University |
Undergraduate Student |
|
30 |
Muhammad Aqif |
Universitas Indonesia (UI) |
Master Student |
|
31 |
Sarah Ali Ali Qazwan |
Universitas Singaperbangsa Karawang |
Undergraduate Student |
|
32 |
Nouraldeen Ameen Abaker Mahmoud |
Universitas Negeri Sebelas Maret (UNS) |
Master Student |
|
33 |
Syeda Sheeza Nadeem |
Universitas Indonesia (UI) |
Master Student |
|
34 |
Muhammad Ramzan |
Universitas Indonesia (UI) |
Master Student |
|
35 |
Musbahu Adam Ahmad |
Universitas Airlangga (UNAIR) |
Doctorate Student |
|
36 |
Ajang Deng Arok Biowei |
State Polytechnic of Malang |
Undergraduate Student |
|
37 |
Felismina Manek Encarnação de Jesus |
Universitas Dian Nuswantoro |
Undergraduate Student |
|
38 |
Aya Ragab |
Universitas Negeri Sebelas Maret (UNS) |
Master Student |
|
39 |
Amadou F Jallow |
Universitas Islam Internasional Indonesia |
Master Student |
|
40 |
Mohammed Ali Hasan Al-Sakkaf |
Universitas Negeri Sebelas Maret (UNS) |
Master Student |
|
41 |
Choirun Nisaa Rangkuti |
Research Center for Quantum Physics (PRFK-BRIN)/Universitas Indonesia (UI) |
Doctorate Student |
|
42 |
Narendar Kumar |
Universitas Indonesia (UI) |
Master Student |
|
43 |
Yanoar P Sarwono |
Research Center for Quantum Physics (PRFK-BRIN) |
Researcher |
|
44 |
Santana Yuda Pradata |
Universitas Gadjah Mada (UGM) |
Undergraduate Student |
|
45 |
Hasna Arista Aprilia |
IPB University |
Undergraduate Student |
|
46 |
Ety Rusydiyati |
IPB University |
Undergraduate Student |
|
47 |
Mufiidah Rizqi Taufiiqoh |
IPB University |
Undergraduate Student |
|
48 |
Muhammad Amri |
Institut Teknologi Bandung (ITN) |
Undergraduate Student |
|
49 |
Marisa Ulfa |
Universitas Negeri Jakarta (UNJ) |
Faculty |
|
50 |
Hilmi Abyan Muzhaffar |
Institut Teknologi Bandung (ITB) |
Undergraduate Student |
|
51 |
Ilham Abdulhakim |
Institut Teknologi Bandung (ITB) |
Undergraduate Student |
|
52 |
Maria Artha Febriyanti Turnip |
Institut Teknologi Bandung (ITB) |
Master Student |
|
53 |
Nur Fadhilah Syarif |
Institut Teknologi Bandung (ITB) |
Doctorate Student |
|
54 |
Maria Gabriela Sabandar |
Institut Teknologi Bandung (ITB) |
Master Sstudent |
|
55 |
Ohod |
Universitas Negeri Sebelas Maret (UNS) |
Master Student |
|
56 |
Adam Gilbran |
Universitas Diponegoro |
Undergraduate student |
|
57 |
Ervin Naufal Arrasyid |
PPET-BRIN |
Research Assistant |
|
58 |
Agna Aldhaka Indra Alam |
Universitas (Negeri) Malang (UM) |
Undergraduate Student |
|
59 |
Wileam Yonathan Phan |
Universitas Indonesia (UI) |
Alumnus |
|
60 |
Fachrizal Rian Pratama |
Universitas Gajah Mada (UGM) |
Doctorate Student |
|
No. |
Name |
Affiliation |
Status |
|
1 |
Edi Suprayoga |
Research Center for Quantum Physics (PRFK-BRIN) |
Researcher |
|
2 |
Sasfan Arman Wella |
Research Center for Quantum Physics (PRFK-BRIN) |
Researcher |
|
3 |
Nadya Amalia |
Research Center for Quantum Physics (PRFK-BRIN) |
Researcher |
|
4 |
M Shoufie Ukhtary |
Research Center for Quantum Physics (PRFK-BRIN) |
Researcher |
|
5 |
Solihin |
Universitas Indonesia (UI) |
Master Graduate |
|
6 |
Nuri Septia Utami |
Universitas Indonesia (UI) |
Master Student |
|
7 |
Achmad Jaelani |
Universitas Indonesia (UI) |
Master Student |
|
8 |
Mohammad Norman Gaza Laksono |
Universitas Indonesia (UI) |
Bachelor Graduate |
|
9 |
Rahmawati Munir |
Universitas Mulawarman |
Faculty |
|
10 |
Riri Murniati |
Universitas Pertahanan RI / BRIN |
Faculty / Postdoc |
|
11 |
Arif Lukmantoro |
Universitas Gadjah Mada (UGM) |
Master student |
|
12 |
Risqi Prastianto Setiawan |
Universitas Diponegoro |
Undergraduate Student |
|
13 |
Rico Martin Sitorus |
Universitas Indonesia (UI) |
Bachelor Alumnus |
|
14 |
Ardimas |
Badan Riset dan Inovasi Nasional (BRIN) |
Postdoc |
|
15 |
Syifa Fauzia Hariyanti Putri |
Kanazawa University |
Doctorate Student |
|
16 |
Luthfiya Kurnia Permatahati |
Universitas Negeri Sebelas Maret (UNS) |
Doctorate Student |
|
17 |
Briant Sabathino Harya Wibawa |
Unversitas Negeri Sebelas Maret (UNS) |
Doctorate Student |
|
18 |
Auliya Rahmatul Ummah |
Universitas Mulawarman |
Faculty |
Poster Abstracts (click each number to show the abstract)
Nonlinear Anomalous Nernst Effect in Noncentrosymmetric Tungsten Ditelluride
Abdurrafi A. Alghifari 1,2, Muhammad Y. Hanna 1, Edi Suprayoga 1∗, and Moh. Adhib Ulil Absor 2
1. Research Center for Quantum Physics, BRIN
2. Department of Physics, UGM
*edi.suprayoga [at] brin.go.id
The generation of anomalous Thermoelectric effect in nonmagnetic materials has garnered
much attention due to the advancement of topological materials. One of the materials showing a large unconventional Thermoelectric effect is the predicted Type-II Weyl Semimetal Tungsten Ditelluride. This study attempts to explain the large value of anomalous Nernst effect in Tungsten Ditelluride via the breaking of inversion symmetry. In spite of the absence of magnetization and external field, the non-centrosymmetric Td-WTe2 bilayer shows a strong Berry Curvature of 1000 A, reveals a large enhancement up to 10^4 times greater than its centrosymmetric monolayer configuration. This ultimately results in the significant value of anomalous Nernst coefficient in Tungsten Ditelluride up to 1 μV/K in 100 Kelvin, comparable to previous reported value from other magnetic materials. Hence, we demonstrated the key role of breaking inversion symmetry in the thermoelectric properties
of the non-centrosymmetric Tungsten Ditelluride.
Dual-Atom Iron Electrocatalyst for Enhanced Oxygen Reduction Reactions
Joel F. Sumbowo 1,2, Farhan A. Ihsan 1,2, Fadjar Fathurrahman 2,3, Nadya Amalia 1, Fiki T. Akbar 4, Hadi T. Yudistira 5, Nadhratun N. Mobarak 6, Hermawan K. DIpojono 2,3, Sasfan A. Wella 1,7*, and Adhitya G. Saputro 2,3
1. Research Center for Quantum Physics, National Research and Innovation Agency (BRIN), South Tangerang 15314, Indonesia.
2. Advanced Functional Materials Research Group, Faculty of Industrial Technology, Institut Teknologi Bandung, Bandung 40132, Indonesia.
3. Research Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Bandung 40132, Indonesia
4. Theoretical High Energy Physics Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40132, Indonesia
5. Mechanical Engineering Study Program, Institut Teknologi Sumatera (ITERA), South Lampung 35365, Indonesia
6. Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia
7. Collaboration Research Center for Advanced Energy Materials, Bandung 40132, Indonesia
*sasfan.arman.wella [at] brin.go.id
Pyrolyzed Fe-N-C catalysts, especially FeN_4, are known for their enhanced catalytic activity, particularly in oxygen reduction reactions (ORR). This study presents a computational analysis of a different Fe-N-C catalyst, Fe_2N_6, adsorbed on graphene, with a focus on graphene nanoribbon edges (zig-zag and armchair) as potential Fe dual-atom catalysts (Fe-DACs). Using density functional theory and microkinetic simulations, we explore the impact of graphitic edges on the stability and ORR activity of Fe-DAC sites. Our results show that zig-zag edges notably reduce the formation energy of Fe-DAC sites, making them more likely to form at these edges. Additionally, several Fe-DAC sites at graphitic edges demonstrate better ORR performance, outperforming the widely used FeN_4 site in single-atom catalyst systems and even surpassing the state-of-the-art Pt(111) catalyst. The (Fe_2N_6)_o@z_1 site, in particular, exhibits exceptional performance in both associative and dissociative mechanisms. These findings underscore the importance of graphitic nanopores in enhancing Fe-DAC catalytic behavior, offering insights for the development of efficient non-precious metal catalysts for ORR applications.
Atomic Asymmetry Effects in 2D Janus Materials
Nadya Amalia 1*, Harry H. Halim 2, Elfi Yuliza 1, Wilin J. Sari 3, Sasfan A. Wella 1
1. Research Center for Quantum Physics, National Research and Innovation Agency (BRIN), Indonesia
2. Department of Precision Engineering, Graduate School of Engineering, Osaka University, Japan
3. Research Center for Climate and Atmosphere, National Research and Innovation Agency (BRIN), Indonesia
*nadya.amalia [at] brin.go.id
Two-dimensional (2D) materials are widely studied for their distinct properties and broad applications. Among these, Janus materials have gained interest due to their unique asymmetric atomic structure. In these materials, the two sides of the monolayer are composed of different elements, such as S, Se, and Te. This broken mirror symmetry leads to specific structural and electronic properties.
In this study, we investigate the structural and electronic properties of CrXY Janus materials (X, Y = S, Se, Te) using first-principles density functional theory (DFT) calculations. Our analysis shows that atomic asymmetry causes variations in lattice parameters and bond characteristics, influencing the material’s stability. The broken mirror symmetry also generates an intrinsic electronic field, which impacts the electronic behavior of the material, as reflected in the electronic band structure and density of states (DOS).
Our findings provide insights into how atomic asymmetry shapes the structural and electronic properties of 2D Janus materials, contributing to a broader understanding of these systems.
High-performance quantum battery with non-linearities
MS Ukhtary 1,2*, CA Downing 2, ART Nugraha 1, AB Cahaya 3, A Rusydi 4, A Majidi 3
1. National Research and Innovation Agency (Indonesia)
2. Univ. of Exeter (United Kingdom)
3. Univ. of Indonesia (Indonesia)
4. National Univ. of Singapore (Singapore)
*msho001 [at] brin.go.id
Quantum battery (QB) is defined as a quantum system that can store energy. The main problem to tackle in QB is to achieve more stored energy with faster charging time. In this work, we consider a model of QB with nonlinearity effect: Kerr nonlinearity and quadratic driving. We show by adding nonlinearity to the system, the performance of the quantum battery in terms of stored energy and charging time becomes better. The Kerr nonlinearity induces anharmonicity in the energy levels of the battery. On the other hand, quadratic driving leads to a squeezed quantum battery, which generates plentiful useful energy near to critical points.
Tunable optical absorption in undoped graphene sandwiched between multilayer dielectric stacks with mirror symmetry
Faisal Kengo 1,2, S Solihin 1,3, M Shoufie Ukhtary 1, Joko Suwardy 1, M Aziz Majidi 2, Ahmad R T Nugraha 1,4,5*
1. Research Center for Quantum Physics, National Research and Innovation Agency (BRIN), South Tangerang 15314, Indonesia
2. Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424, Indonesia
3. Department of Physics, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia
4. Department of Engineering Physics, Telkom University, Bandung 40257, Indonesia
5. Research Collaboration Center for Quantum Technology 2.0, Bandung 40132, Indonesia
∗ahmad.ridwan.tresna.nugraha [at] brin.go.id
We investigate the optical absorption of an undoped graphene monolayer when it is put in a one-dimensional multilayer stack. Using the transfer matrix method, we derive explicit formulas for the optical absorption of the graphene monolayer at the center of the dielectric stack and find that the optical absorption uniquely depends on repetition number r and the unit layers structure. When sandwiched between unit layers structure composed of three
dielectric materials (referred to as the “ABC” structure) with even values of r, the graphene monolayer absorbs 2.3% of visible to near-infrared light. This behavior is the same as if graphene were free-standing, not sandwiched between the dielectric stack. In contrast to that situation, in the ABC structure with odd values of r, also when the graphene monolayer is sandwiched between four materials (the “ABCD” structure) with any values of r, we can obtain optical absorption as large as 50% at particular refractive indices n of the constituent dielectric materials. The 50%-absorption is, in fact, the maximum optical absorption for any undoped monolayer material in the symmetric dielectric stacks. By varying r and n within the ABC or ABCD structures, we can finely adjust the optical absorption of graphene within the range of 0–50%, facilitating precise control for various optoelectronic applications
Effect of Scattering Rate and Thickness Variation on the Propagation of Surface Plasmon Polariton (SPP) in Topological Weyl Semimetals Waveguide
N S Utami 1*, M A Majidi 1*, M S Ukhtary 2*, A Budiyono 2
1. University of Indonesia
2. Research Center for Quantum Physics, National Research and Innovation Agency (BRIN)
*nuriseptiautami [at] gmail.com
The generation of anomalous Thermoelectric effect in nonmagnetic materials has garnered
much attention due to the advancement of topological materials. One of the materials showing a large unconventional Thermoelectric effect is the predicted Type-II Weyl Semimetal Tungsten Ditelluride. This study attempts to explain the large value of anomalous Nernst effect in Tungsten Ditelluride via the breaking of inversion symmetry. In spite of the absence of magnetization and external field, the non-centrosymmetric Td-WTe2 bilayer shows a strong Berry Curvature of 1000 A, reveals a large enhancement up to 10^4 times greater than its centrosymmetric monolayer configuration. This ultimately results in the significant value of anomalous Nernst coefficient in Tungsten Ditelluride up to 1 μV/K in 100 Kelvin, comparable to previous reported value from other magnetic materials. Hence, we demonstrated the key role of breaking inversion symmetry in the thermoelectric properties
of the non-centrosymmetric Tungsten Ditelluride.
Study of the Six-Dimensional Potential of Two-Electron System Ground State Energy with Neural Network
Achmad Jaelani 1, Yanoar Pribadi Sarwono 2*, Muhammad Aziz Majidi 1
1. Universitas Indonesia
2. National Research and Innovation Agency (BRIN)
*yano001 [at] brin.go.id
In this study, we address the challenge of predicting the ground state energy of a two-electron system using a deep neural network. We generate a dataset by solving the Schrödinger equation for a two-electron system and then train a convolutional neural network to predict the ground state energy based on a six-dimensional potential representation. Within a relatively small grid space, our predictions for the ground state energy closely match the exact values. Our results highlight the promising potential of deep learning in managing multi-electron systems.
Thermoelectric Properties of Type-I and Type-II Nodal Line Semimetals: A Comparative Study
Mohammad Norman Gaza Laksono 1*, M. Aziz Majidi 2, ART Nugraha 1
1. Research Center for Quantum Physics, National Research and Innovation Agency (BRIN), South Tangerang 15314, Indonesia;
2. Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424, Indonesia
*norman.gaza [at] gmail.com
We investigate the thermoelectric (TE) properties of Nodal Line Semimetals (NLSs) using a combination of semi-analytical calculations of Boltzmann’s linear transport theory with the relaxation time approximation, along with first-principles calculations for type-I (type-II) NLS. We consider these materials’ conduction and valence bands that cross near the Fermi level from the band structure obtained through first-principles calculations by using the two-band model through fitting to find the initial value of energy dispersion parameters for each energy band from both types of the material, namely Fermi velocity $v_{F}$ and effective mass $m$. We try to find the optimum curvature value for each energy band by tuning those parameter values to improve its TE Properties. Our calculation results show that for type-I NLS we obtain $\sim3.5\%$ increase of Seebeck coefficient peak value compared to those using initial parameter value from $0.509S_{0}$ to $0.527S_{0}$ when $m=0.2m_{0}$ where $S_{0} = k_{B}/e \approx 86.17 \,\, \upmu \mathrm{V/K}$. Meanwhile, for type-II NLS we obtain a $\sim83\%$ in power factor when $v_{F}$ is lowered. In addition, by comparing all of our calculation results, we observed that tuning $v_{F}$ has a more significant impact on improving TE properties in both type of NLS compared to tuning $m$. We believe our work can trigger similar calculations on other materials in order to scan the TE potential of the materials by manipulating the band structure by varying the curvature of its energy band.
Optimization of TiO₂-Eggshell Composite for Enhanced Photocatalytic Degradation of Methylene Blue
Rahmawati Munir 1*, Dadan Hamdani 1, dan Sahara Hamas Intifadhah 1
1. Theoretical and Material Physics Laboratory, Department of Physics, Mathemathics and Natural Science, Mulawarman University, Jl. Barong Tongkok No. 4, Samarinda, Kalimantan Timur, 75123
*rahmawati [at] fmipa.unmul.ac.id
This research explores the synthesis and application of eggshell powder (ESP) composite with titanium dioxide (TiO₂) in water purification efforts through the degradation of methylene blue (MB). The CT-TiO₂ composite material was synthesized using the Solid State Dispersion (SSD) method. Testing showed that an increase in MB concentration led to an increase in absorbance on the UV-VIS Spectrophotometer, with the optimum mass found in the CT sample with 2% TiO₂ (CT-2%TiO₂). All composite samples exhibited MB degradation efficiency of over 95%, indicating the high capability of the composite in MB photodegradation with UV light. Additionally, the use of CT-TiO₂ composite also increased the solution’s pH from 6.72 to 7.91. These results affirm the potential of CT-TiO₂ composite as an effective and environmentally friendly solution for purifying water contaminated with methylene blue, improving water quality while optimizing pH parameters for broader applications.
Enhancing airless tire performance for military vehicles: natural rubber compound with carbon black Fillers N220 and N550 with dynamic mechanical analysis approach
Riri Murniati 1,2*, Arini Fitria Gunawan 2, Ade Sholeh Hidayat 1, Liszulfah Roza 1, Dewi Kusuma Arti 1 Indriasari 1, Akhmad Amry 1,2, Mikrajuddin Abdullah 3
1. Advanced Materials Research Center, National Research and Innovation Agency (BRIN), Banten 15314, Indonesia
2 Study Program of Physics, Indonesia Defense University, IPSC Sentul, Bogor 16810, Indonesia
3 Department of Physics, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132, Indonesi
*ririmurniati90 [at] gmail.com
During and after the COVID-19 pandemic, the world has become more aware of environmental concerns and the importance of sustainability. Using natural rubber instead of synthetic rubber is one step toward a greener environment in a variety of technological applications, including the fabrication of vehicle tires. The objective of this work is to optimize the formulation for the production of airless tires, primarily for military vehicle applications, using natural rubber. Two natural rubber types, SIR 20 and RSS 1, with carbon black variants N220 and N550 as reinforcing agents present novel synergistic efects, and potentially tailor the properties of the rubber compound more precisely to meet the demanding requirements of military vehicle tires. A comprehensive assessment was conducted to evaluate various physical, damping, processing, and mechanical properties under standard conditions and subsequent aging at 70 °C for 72 h. Comparative analysis against control samples revealed notable improvements, particularly in abrasion resistance, crucial for tire wear. The combination of RSS 1 and CB N220 showed signifcant enhancements in strength and rigidity, suggesting their viability as alternative fllers. Leveraging dynamic mechanical analysis (DMA) results, the rubber compound underwent optimization to meet airless tire requirements, encompassing durability, comfort, and performance. This nuanced understanding of rubber’s viscoelastic behavior holds paramount importance in designing puncture-resistant airless tires with optimal performance attributes. Combination of innovative materials and advanced characterization techniques to address the specifc challenges of enhancing airless tire performance for military vehicles in challenging operational environments.
Keywords: Non-pneumatic tires · Vulcanized Carbon Fillers · Viscoelastic damping · Dynamic mechanical analysis (DMA) · Defense Applications
One-Dimensional Confined Rashba States in 2D Si2Bi2 Induced by Vacancy Line Defect
Arif Lukmantoro 1,2*, Edi Suprayoga 2, Moh.Adhib Ulil Abshor 1
1. Departement of Physics, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara BLS 21 Yogyakarta 55186 Indonesia
2. Research Center for Quantum Physics, National Research and Innovation Agency, Tangerang Selatan 15314, Indonesia.
*ariflukmantoro [at] mail.ugm.ac.id
By using first-principles calculations, we have investigated the one-dimensional Silicon vacancy line defect (VLD) on 2D Si2Bi2 . The electronic band calculation implies that Si-VLD in 2D Si2Bi2 emerged the defect states crossing the Fermi Level indicating the metallic character of materials. Including the spin-orbit coupling (SOC) calculations, we reveal that the defect states have a giant spin splitting observed at the Γ-Y line of the first Brillouin zone, dominated by p-p coupling orbital from the atom near the VLD-site. Furthermore, the spin-polarized calculations complemented by symmetry analysis, we reveal that Si-VLD in Arm-chair directions induces the unidirectional Rashba spin states, making this 2D material ideal for studying spin-transport phenomena and realizing energy savings in spintronics applications.
Carbon and Graphene Quantum Dot in the Application of Science and Development of Environmentally Friendly Technology Towards a Sustainable Future
Risqi Prastianto Setiawan 1* and Adam Gilbran 2
1. Departement of Physics, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara BLS 21 Yogyakarta 55186 Indonesia
2. Research Center for Quantum Physics, National Research and Innovation Agency, Tangerang Selatan 15314, Indonesia.
*risqiprastiantosetiawan [at] gmail.com
The application of nanomaterials in the field of technology and their manipulation at the nanometer scale (10^(-9) m) is referred to as nanotechnology. At the nanometer scale, a material can exhibit very different properties compared to its macroscopic scale. These properties include increased strength, chemical reactivity, electrical conductivity, and optical properties. Meanwhile, materials that undergo manufacturing, processing, and use on a nanometer scale are called nanomaterials. Nanomaterials can take the form of nanoparticles, nanowires, nanorods, nanofilms, or nanocomposites. There are new nanomaterials called quantum dots that were recently discovered and developed in the early 21st century. Materials made with quantum dots that have been developed recently are carbon and graphene, so they are called Carbon Quantum Dots (CQDs) and Graphene Quantum Dots (GQDs). Both materials are being developed and applied in various fields such as sensors, biomedicine, optoelectronics, energy, supercapacitors, LED lights, electro-catalysis, and fluorescent film coatings. CQDs have outstanding fluorescence properties, biocompatibility, good stability making them ideal candidates for application in bioimaging, sensors, and optoelectronic devices. GQDs have unique properties such as high electron mobility, thermal conductivity, and large reaction surface area with fluorescence from quantum dots. Both materials can be synthesized by 2 methods, namely top-down and bottom-up. The top-down method is the main approach to synthesize CQDs and GQDs that involves breaking large carbon structures into smaller nanostructures. Some of the top-down methods used are chemical and physical exfoliation as well as laser burning and ablation. In addition, bottom-up methods involve the construction of quantum dots from carbon through chemical reactions. Some of the methods used are hydration carbonization, polymerization, and dehydration. So that the development of Carbon Quantum Dots (CQDs) and Graphene Quantum Dots (GQDs) materials has great potential in science and technology to be studied and developed further in the future.
Keywords: Carbon Quantum Dots (CQDs), Graphene Quantum Dots (GQDs), laser ablation, nanomaterial, nanotechnology
Enhancement of spin-mixing conductance by s-d orbital hybridization in heavy metals
Adam B. Cahaya 1*, Rico M. Sitorus 1, Anugrah Azhar 2, Ahmad R. T. Nugraha 3, Muhammad Aziz Majidi 1
1.Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424, Indonesia
2.Physics Study Program, Faculty of Sciences and Technology, Syarif Hidayatullah State Islamic University Jakarta, South Tangerang 15412, Indonesia
3. Research Center for Quantum Physics, National Research and Innovation Agency (BRIN), South Tangerang 15314, Indonesia
*adam [at] sci.ui.ac.id
Spin transfer torque in a multilayer magnetic system can be understood in terms of interaction between a normal metal and a ferromagnetic layer on the multilayer, in which the interaction is characterized by the magnetic susceptibility. Most of experimental studies on this subject utilizes heavy metals, such as Pd and Pt, while a recent theory assumes a light metal as the normal metal. We aim to reconcile this discrepancy and achieve consistency with the experiments by studying magnetic susceptibility of Pd and Pt. We theoretically investigate the complex magnetic susceptibility of Pd and Pt by combining Tight-binding Approximation, Hubbard Model, and Density Functional Theory. We calculate a single band susceptibility for Pd and Pt.Our results show that the band structure is dominated by the d-orbitals and the susceptibility is enhanced by its large repulsive interaction.
In a magnetic multilayer, the spin transfer between localized magnetization dynamics and itinerant conduction spin arises from the interaction between a normal metal and an adjacent ferromagnetic layer. The spin-mixing conductance then governs the spin-transfer torques and spin pumping at the magnetic interface. Theoretical description of spin-mixing conductance at the magnetic interface often employs a single conduction-band model. However, there is orbital hybridization between conduction s electron and localized d electron of the heavy transition metal, in which the single conduction-band model is insufficient to describe the s-d orbital hybridization. In this work, using the generalized Anderson model, we estimate the spin-mixing conductance that arises from the s-d orbital hybridization. We find that the orbital hybridization increases the magnitude of the spin-mixing conductance.
Pressure-Induced Emission Enhancement and Piezochromism of Lead-Free Double Perovskte Cs2TiBr6
Ardimas 1, Edi Suprayoga 2*, and Thiti Bovornratanaraks 3
1. BRIN Research Center for Quantum Physics
2. BRIN Research Center for Quantum Physics
3. Department of Physics, Faculty of Science, Chulalongkorn University
*edi.suprayoga [at] brin.go.id
For optoelectronic devices, lead-free halide double perovskite (HDP) has attracted a lot of scientific attention. In this case, we present the first evidence of a pressure-induced phase transition in Cs2TiBr6 as a practical means of adjusting its optical characteristics. Using a complete aqueous solution technique, we were able to successfully synthesize the HDP based on Cs2TiBr6. By putting the sample into diamond anvil cells (DACs) and using Raman spectroscopy, we were able to study the pressure dependency phase transition and photoluminescence (PL). Under compression, we found piezochromism of Cs2TiBr6 change from red to dark black. The PL emission then exhibits a red shift and a large widening at pressures up to 12.6 GPa. These results demonstrate that pressure affects the octahedral vibration modes of TiBr6 and is associated with a higher number of self-trap excitons (STE) states. Consequently, our research on high-pressure technology offers insight into the structure-property correlations to improve Cs2TiBr6 performance.
First-principles study of stacking-dependent anomalous valley Hall effect in WTe2/CrI3 van der Waals heterostructure
Syifa Fauzia Hariyanti Putri 1*, Naoya Yamaguchi 2, Fumiyuki Ishii 2
1. Division of Mathematical and Physical Science, Graduate School of Natural Science and Technology,
Kanazawa University, Kakuma, Kanazawa, 920-1192, Japan
2. Nanomaterials Research Institute, Kanazawa University, Kakuma, Kanazawa, 920-1192, Japan
*syifaputri [at] stu.kanazawa-u.ac.jp
The valley property of electrons has become a key area of interest in condensed matter physics, offering potential for innovative electronic devices[1]. This property is sought to be utilized through the manipulation of valley-polarized carriers. Monolayer WTe2 exhibits notable characteristics, including strong spin-orbit interactions, valley degeneracy at 𝐾 and −𝐾 points, and preserved time reversal symmetry[2]. However, breaking these valleys degeneracy requires high external magnetic field [3]. One way to overcome this limitation is through the introduction of CrI3 magnetic layer to WTe2 monolayer [4,5]. In addition, the time-reversal symmetry in WTe2/CrI3 can be broken resulting in measurable anomalous Hall conductivity (AHC). The anomalous valley Hall effect results from spontaneous valley polarization. Our study investigated various stacking configurations of WTe2/CrI3 heterostructures. We demonstrated that both AHC and valley splitting are dependent on the specific stacking arrangement. Our results indicate that modifying the relative positions of the layers could provide a novel approach to achieving the anomalous valley Hall effect in these layered systems.
References
1) J.R. Schaibley, H. Yu, G. Clark, P. Rivera, J.S. Ross, K. L. Seyler, W. Yao, X. Xu: Nat. Rev. Mater.1, 16055 (2016).
2) J. Kang, S.Tongay, J.Zhou, J.Li, J.Wu: Appl. Phys. Lett. 102(1), 012111 (2013).
3) D. MacNeill, C.Heikes, K. F. Mak, Z. Anderson, A. Kormányos, V. Zólyomi, J. Park, and D. C. Ralph: Phys. Rev. Lett. 114, 037401 (2015).
4) H. Zhang, W. Yang, Y. Ning, X. Xu: Phys. Rev. B. 101, 205404 (2020).
5) L. Xu, M. Yang, L. Shen, J. Zhou, T. Zhu, Y. P. Feng: Phys. Rev. B. 97, 041405 (2018).
Fractional Klein-Gordon equation with Hulthen potential and the optical properties of diatomic molecules under the magnetic field and topological defects
Luthfiya Kurnia Permatahati 1*
1. UNS
*luthfiyakp_1997@student.uns.ac.id
We investigate the optical properties of some diatomic molecules modelled by Hulthen potential under external magnetic field and topological defects. The Klein Gordon equation in the domain of General Fractional Derivative (GFD) with Hulthen potential and a position-dependent mass formalism in the topological effect and magnetic field is solved by using GFD Nikiforov-Uvarov (NU) method to obtain the energy equation and normalized wave function. The effect of the topological defect, magnetic field, and fractional parameter values on the energy eigenvalue was discussed. The results show that those parameters cause a shift in the energy spectrum. In addition, the optical properties were examined by calculating the absorption coefficient and refractive index changes of the quantum system.
Effect of rainbow gravity, PDM, and external magnetic field on optical properties GaAs quantum dot
Briant Sabathino Harya Wibawa (1)*
1. UNS
*s3.fisika_briant@student.uns.ac.id
The Klein–Gordon equation in cosmic strings within RG spacetime under the influence of an external magnetic field and Coulomb potential for position-dependent mass (PDM) particles is investigated using the Nikiforov-Uvarov (NU) method. Energy levels and wave functions are obtained from the solution of the Klein–Gordon system with PDM particles. We apply three rainbow functions to calculate the energy and optical properties of refractive index coefficient (RIC) and absorption coefficient (AC) for GaAs quantum dot (QD). Our results show that the linear, third-order nonlinear, and total RIC and AC increase and shift toward higher energies as the magnetic field increases for one pairs of rainbow functions. Similarly, the linear, third-order nonlinear, and total RIC and AC increase and shift toward lower energies as the parameters of the rainbow function and PDM increase for one pairs of rainbow functions. Furthermore, the total RIC and AC decrease as the optical intensity increases for one pairs of rainbow functions.
Effects of Fumed Silica and PMMA on the Optical Properties of Blue-Emitting Perovskite Nanocrystals
Auliya Rahmatul Ummah1,2, Ea Cahya Septia Mahen4, Ferry Iskandar3
1. Theoretical and Material Physics Laboratory, Department of Physics, Mathematics and Natural Science, Mulawarman University, Jl. Barong Tongkok No. 4, Samarinda, Kalimantan Timur, 75123
2. Electronics and Instrumentation Laboratory, Department of Physics, Mathematics and Natural Science, Mulawarman University, Jl. Barong Tongkok No. 4, Samarinda, Kalimantan Timur, 75123
3. Department of Physics, Institut Teknologi Bandung, Bandung, Indonesia
4. Department of Physics Education, UIN Sunan Gunung Djati, Bandung, Indonesia
*auliyarahmatul.ummah [at] gmail.com
Achieving highly efficient blue organic-inorganic halide perovskites (OIHP) with superior optical properties has been a challenging task and remains a key area of interest. In this study, we have successfully synthesized blue-emitting CH3NH3PbBr3 perovskite using a ligand-assisted reprecipitation method and subsequently embedded it in a fumed silica and PMMA matrix. The addition of fumed silica caused a blueshift in the photoluminescence (PL) peak of CH3NH3PbBr3 from 481 to 477 nm. Further embedding of the OIHP in a PMMA matrix led to an additional blueshift from 477 nm to 471 nm. The OIHP absorbance spectrum also shifted from 451 nm to 426 nm, which aligns with the blueshift observed in the PL peak spectrum. The emergence of two peaks in the absorbance spectrum suggests the formation of nanoplates with a small number of layers (n=2 and n=4) on the OIHP, indicating a strong quantum confinement effect. These results suggest that CH3NH3PbBr3/SiO2-PMMA composite films exhibit excellent optical properties, making them promising for optoelectronic applications.
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