DQMP Forum - Development of electron diffraction in Geneva - Ballistic-to-diffusive transition in spin chains with broken integrability

20.04.2021 13:00 – 14:30

Development of electron diffraction in Geneva
Céline Besnard, Group of Prof. Cerny
Yashar Sadian, Group of Prof. Cerny

The Electron Microscopy Platform (CryoGEnic) and the Laboratory of Crystallography are working to implement electron diffraction in Geneva. I will briefly present the advantages of this structural method and the setup available at the CryoGEnic Platform, including a new solid-state detector that is going to be installed in June.


Ballistic-to-diffusive transition in spin chains with broken integrability
Joao Ferreira, Group of Prof. Giamarchi

Understanding the mechanisms behind the different transport regimes in correlated materials is a major goal in the quantum-matter community. In particular, interacting one-dimensional geometries provide a rich panoply of transport physics, ranging from super-ballisticity to many-body-localization. It is common knowledge that generic interactions should lead to diffusive transport in the long run. But what makes an interaction generic enough? In this work, we study the emergence of diffusion in the spin transport of a weakly-perturbed XXZ spin-1/2 chain. We find that, depending on the strength of the perturbation, diffusive transport is anteceded by a novel “quasi-ballistic” regime. This regime persists up to parametrically large system sizes and it is characterized by a strong renormalization of the spin current. I will also present my ongoing work on the effects of dephasing in the transport of fermionic chains.

Lieu

By Zoom meeting

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