Dr
Anna
Kauch
Institute of Solid State Physics, TU Wien, Austria
Susceptibilities and optical conductivity are examples of two-particle response functions that are the key quantities for connecting theoretical predictions for correlated materials with experimental results. It can however become highly non-trivial to calculate them, especially in cases when nonlocal electronic correlations are important.
In my talk I will explain what two-particle correlations are and when they become important. I will then present an overview of methods of their computation with the focus on diagrammatic methods. I will show results for two-particle (vertex) corrections to optical conductivity [1], that are present in systems with antiferromagnetic or charge density wave fluctuations, leading to a displaced Drude peak in correlated metals [2]. At the end I will discuss computational
challenges and new methodological developments in the efficient representation of two-particle correlation functions with the use of quantics tensor trains [3,4].
[1] A. Kauch, P. Pudleiner, K. Astleithner, P. Thunström, T. Ribic, and K. Held, Phys. Rev. Lett. 124, 047401 (2020)
[2] J. Krsnik, O. Simard, P. Werner, A. Kauch, and K. Held, Phys. Rev. B110, 075118 (2024)
[3] H. Shinaoka, M. Wallerberger, Y. Murakami, K. Nogaki, R. Sakurai, P. Werner, and A. Kauch, Phys. Rev. X 13, 021015 (2023)
[4] S. Rohshap, M. Ritter, H. Shinaoka, J. von Delft, M. Wallerberger,
and A. Kauch, Phys. Rev. Res. 7, 023087 (2025)
This is a hybrid event:
Room D, the Institute of Physics PAS, Al. Lotników 32/46
Online: Zoom Link, (Passcode: 134595, Meeting ID: 823 8038 0442)
