Tensor network approaches to the study of the interplay of large localized systems and small thermal grains

Abstract: In isolated quantum many-body systems, thermalization is believed to occur due to the ergodicity of the system. While most physical systems indeed behave in an ergodic way and their dynamics leads to thermal equilibrium, some outstanding counterexamples exist. Many-body localization (MBL) provides a paradigmatic case of ergodicity-breaking, where strong disorder leads to the lack of relaxation to the thermal equilibrium.

In this talk I will present recent studies of the interplay of large non-interacting localized chains and small ergodic baths. Using matrix product state (MPS) methods, we probe the dynamics of these systems, showing that in the strong interaction case not only the localized chain does not thermalize, but it also leads to the localisation of the bath, a phenomenon known as MBL proximity effect. The presence of the thermal inclusion, however, leads to a dramatic change in the system, as it makes the localized particles interact. As a consequence, interesting entanglement patterns arise in the chain, a feature we dubbed propagation of MBL. Thanks to a phenomenological theory, we are able to link the localisation of the thermal grain and the phenomenon of propagation of MBL, reproducing the characteristic entanglement behavior.

condensed matterHEP - theory

Audience: researchers in the topic

Numerical Methods in Theoretical Physics