Sebastian Stengele, Technical University of Munich

26/03/2026 10:00h, Aula Seminari MOX VI Piano, Nave (bd. 14), Politecnicno di Milano

Abstract: Calderbank-Shor-Steane (CSS) codes, such as the toric code, are a widely studied class of quantum error-correcting codes. Understanding the thermalization time of these systems is important not only for error correction but also for applications like Gibbs sampling. 

We show that CSS codes on a lattice satisfy a modified logarithmic Sobolev inequality and thus thermalize rapidly in any dimension at sufficiently high temperatures. For a special subclass, this rapid thermalization even holds at all positive temperatures. The central idea underlying our approach is to exploit the structure of CSS codes to decompose a quantity into two simpler, (almost) classical components, allowing us to apply tools from classical statistical mechanics to analyze the thermalization. In the last part I will show how this method generalizes to 2D Abelian quantum double models.

This is joint work with Ángela Capel, Li Gao, Angelo Lucia, David Pérez-García, Antonio Pérez-Hernández, Cambyse Rouzé and Simone Warzel.