The modified logarithmic Sobolev inequality for quantum spin systems via approximate tensorization

Angela Capel
Technische Universität München

Given a uniform, frustration-free family of local Lindbladians defined on a quantum lattice spin system in any spatial dimension, we prove a strong exponential convergence in relative entropy of the system to equilibrium under a condition of spatial mixing of the stationary Gibbs states and the rapid decay of the relative entropy on finite-size blocks. Our result leads to the first examples of the positivity of the modified logarithmic Sobolev inequality for quantum lattice spin systems independently of the system size. Moreover, we show that our notion of spatial mixing is a consequence of the recent quantum generalization of Dobrushin and Shlosman's complete analyticity of the free-energy at equilibrium. The latter typically holds above a critical temperature. The main ingredient in the proof is a newly derived approximate tensorization of the relative entropy. This talk is mainly based on joint work with Cambyse Rouzé and Daniel Stilck França.

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