Starts 16 Jun 2026 14:30
Ends 16 Jun 2026 15:30
Central European Time
CMSP News and Views Seminar Series: Seeing the Unseen: Multipole Analysis and Emergent Phenomena in Condensed Matter
Lagrange Lecture Hall (Leonardo Building) and via Zoom
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Light refreshments will be served prior the seminar
at 14:00 on the Leonardo Building terrace
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Sayantika Bhowal
(Indian Institute of Technology Bombay)
Light refreshments will be served prior the seminar
at 14:00 on the Leonardo Building terrace
- - -
Sayantika Bhowal
(Indian Institute of Technology Bombay)
Abstract:
Understanding and foreseeing novel and emergent properties of condensed matter systems have been of immense interest in recent times, not only in the context of fundamental research but also for their advanced functional applications. While the development of density functional theory has been a breakthrough in theoretical approaches for a realistic description of solid-state materials, predicting material properties still remains a challenging task. This is partly related to the absence of any systematic approach to account for and understand the physical properties of real systems.
In my talk, I will discuss the "multipole analysis" approach, which emerges as a systematic and powerful method to understand a wide range of physical phenomena in condensed matter systems within a unified framework, and consequently to accelerate the search for emerging phenomena in such systems. The success of this approach lies in the fact that it allows a complete characterization of the charge and magnetization densities of these systems, which in turn are responsible for their emergent properties. After introducing the importance of multipole analysis, I will provide an overview of recent advancements in this approach by focusing on its contributions and successes in addressing some fundamental problems in physics [1–3]. Finally, I will discuss some of our contributions to this field [4–9], with a focus on our recent work [9–15] on understanding and controlling non-relativistic spin splitting in antiferromagnets based on the multipolar framework.
While noticeable progress has been made so far, there are still many open directions to explore in the future. Through this progress, we hope to establish multipolar theory as a unified framework for the description of condensed matter systems, which is not only useful for predicting material properties but also provides a platform for designing novel materials with advanced functionalities that can be synthesized and characterized experimentally.
References:
[1] B. B. V. Aken et. al., Nature 449, 702-705 (2007); N. A. Spaldin, M. Fiebig, and M. Mostovoy, J. Phys.: Condens. Matter 20, 434203 (2008).
[2] N. A. Spaldin et. al., Phys. Rev. B 88, 094429 (2013); H. Watanabe and Y. Yanase, Phys. Rev. B 98, 245129 (2018).
[3] M.-T. Suzuki et. al., Phys. Rev. B 95, 094406 (2017) ; M. Kimata et. al., Nat. Comm. 12, 5582 (2021).
[4] S. Bhowal and N. A. Spaldin, Phys. Rev. Lett. (Editors' suggestion) 128, 227204 (2022).
[5] S. Bhowal and S. Satpathy, Phys. Rev. B (Rapid Comm.) 101, 121112 (2020).
[6] S. Bhowal and G. Vignale, Phys. Rev. B (Editors' suggestion) 103, 195309 (2021).
[7] S. Bhowal, S. P. Collins and N. A. Spaldin, Phys. Rev. Lett. 128, 116402 (2022).
[8] S. Bhowal and N. A. Spaldin, Phys. Rev. Research 3, 033185 (2021).
[9] S. Bhowal and N. A. Spaldin, PRX 14, 011019 (2024).
[10] S. Bhowal, A. Urru, S. F. W., and N. A. Spaldin, Phys. Rev. Lett. 134, 146703 (2025).
[11] S. Bandyopadhyay, S.Picozzi, and S. Bhowal, Phys. Rev. B 112, 064405 (2025).
[12] S. Bandyopadhyay et. al., PRB 112, L100402 (2025).
[13] A. Ray, S. Bandyopadhyay, S. Bhowal, arXiv:2509.20041 (2025).
[14] S. Bhowal and A. Bose, arXiv: 2510.20306v1 (2025).
[15] Muskan, S. Bandyopadhyay, and S. Bhowal, arXiv:2602.14608 (2026).
In my talk, I will discuss the "multipole analysis" approach, which emerges as a systematic and powerful method to understand a wide range of physical phenomena in condensed matter systems within a unified framework, and consequently to accelerate the search for emerging phenomena in such systems. The success of this approach lies in the fact that it allows a complete characterization of the charge and magnetization densities of these systems, which in turn are responsible for their emergent properties. After introducing the importance of multipole analysis, I will provide an overview of recent advancements in this approach by focusing on its contributions and successes in addressing some fundamental problems in physics [1–3]. Finally, I will discuss some of our contributions to this field [4–9], with a focus on our recent work [9–15] on understanding and controlling non-relativistic spin splitting in antiferromagnets based on the multipolar framework.
While noticeable progress has been made so far, there are still many open directions to explore in the future. Through this progress, we hope to establish multipolar theory as a unified framework for the description of condensed matter systems, which is not only useful for predicting material properties but also provides a platform for designing novel materials with advanced functionalities that can be synthesized and characterized experimentally.
References:
[1] B. B. V. Aken et. al., Nature 449, 702-705 (2007); N. A. Spaldin, M. Fiebig, and M. Mostovoy, J. Phys.: Condens. Matter 20, 434203 (2008).
[2] N. A. Spaldin et. al., Phys. Rev. B 88, 094429 (2013); H. Watanabe and Y. Yanase, Phys. Rev. B 98, 245129 (2018).
[3] M.-T. Suzuki et. al., Phys. Rev. B 95, 094406 (2017) ; M. Kimata et. al., Nat. Comm. 12, 5582 (2021).
[4] S. Bhowal and N. A. Spaldin, Phys. Rev. Lett. (Editors' suggestion) 128, 227204 (2022).
[5] S. Bhowal and S. Satpathy, Phys. Rev. B (Rapid Comm.) 101, 121112 (2020).
[6] S. Bhowal and G. Vignale, Phys. Rev. B (Editors' suggestion) 103, 195309 (2021).
[7] S. Bhowal, S. P. Collins and N. A. Spaldin, Phys. Rev. Lett. 128, 116402 (2022).
[8] S. Bhowal and N. A. Spaldin, Phys. Rev. Research 3, 033185 (2021).
[9] S. Bhowal and N. A. Spaldin, PRX 14, 011019 (2024).
[10] S. Bhowal, A. Urru, S. F. W., and N. A. Spaldin, Phys. Rev. Lett. 134, 146703 (2025).
[11] S. Bandyopadhyay, S.Picozzi, and S. Bhowal, Phys. Rev. B 112, 064405 (2025).
[12] S. Bandyopadhyay et. al., PRB 112, L100402 (2025).
[13] A. Ray, S. Bandyopadhyay, S. Bhowal, arXiv:2509.20041 (2025).
[14] S. Bhowal and A. Bose, arXiv: 2510.20306v1 (2025).
[15] Muskan, S. Bandyopadhyay, and S. Bhowal, arXiv:2602.14608 (2026).