Résumé |
Most conventional experimental probes used in condensed matter systems can be interpreted through the
framework of linear
response. There are however cases where linear response functions alone are insufficient to discriminate
between different physical
scenarios. In these situations, nonlinear response functions could provide a valuable resource to sharpen our
understanding.
However, currently, a major limitation is the ability to provide a qualitative interpretation to the measured
signals. In this talk I will
discuss two setups where the long-time divergence of nonlinear response functions can be understood and
potentially provide
insights into condensed matter systems.In the first part of the seminar, I will show that long-time divergences
in systems with non-
topological excitations are produced by scattering processes [1,2]. In the second part, I will focus on 2D
quantum systems with
topological order and featuring anyonic excitations. I will argue that in this case a stronger long-time
divergence appears, which
could used as a unique fingerprint of anyons in experimental systems [3].
[1] MF, S. Gopalakrishnan, R. Vasseur, F. Essler, S. A. Parameswaran, arXiv:2208.09490
[2] MF, S. Gopalakrishnan, R. Vasseur, S. A. Parameswaran, F. Essler, in preparation
[3] M. McGinley, MF, S. A. Parameswaran, arXiv:2210.16249 |