N. LAFLORENCIE: Many-body localization and topological order in disordered interacting Ising-Majorana chains

         I will start by giving 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