Recorded 31 March 2025. Daniel Stilck Franca of the University of Copenhagen presents "Optimal quantum algorithm for Gibbs state preparation" at IPAM's Optimal Transport for Density Operators: Theory and Numerics Workshop. Abstract: It is of great interest to understand the thermalization of open quantum many-body systems, and how quantum computers are able to efficiently simulate that process. A recently introduced disispative evolution, inspired by existing models of open system thermalization, has been shown to be efficiently implementable on a quantum computer. By resorting to the so-called oscillator norm of an observable, we prove that, at high enough temperatures, this evolution reaches the Gibbs state in time scaling logarithmically with system size. The result holds for Hamiltonians that satisfy the Lieb-Robinson bound, such as local Hamiltonians on a lattice, and includes long-range systems. To the best of our knowledge, these are the first results rigorously establishing the rapid mixing property of high-temperature quantum Gibbs samplers, which is known to give the fastest possible speed for thermalization in the many-body setting. This is joint work with Cambyse Rouzé and Álvaro Alhambra and is based on https://arxiv.org/pdf/2411.04885 . Learn more online at: https://www.ipam.ucla.edu/programs/workshops/workshop-i-optimal-transport-for-density-operators-theory-and-numerics/?tab=schedule