1. many-body localization and topological order in disordered interacting ising-majorana chains

Nicolas Laflorencie

CNRS, France

15 February 2022 Tue 5 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

In this seminar, I will first give a general introduction to the so-called Many-Body Localization (MBL) phenomenon which occurs in a large class of disordered and interacting quantum systems. Then, I will discuss our recent results [1] obtained for Z2-symmetric disordered interacting Ising-Majorana chains at high energy for which a very rich phase diagram emerges with two distinct MBL regimes separated by a broad ergodic phase. We have also found that localization-protected topological edge states survive interactions, and are always associated with a many-body spectral pairing. In contrast, any interaction destabilizes the (non-interacting) infinite randomness critical point towards thermalization, and we show evidence that its close vicinity also gets delocalized by weak interactions, as long as the typical localization length remains larger than the so-called avalanche threshold.

[1] NL, G. Lemarié, and N. Macé, arXiv:2201.00556