Special Session 58: Recent Advances in Numerical Methods for Partial Differential Equations

Efficient quantum Gibbs samplers

Bowen Li
City University of Hong Kong
Hong Kong
Co-Author(s):    
Abstract:
Lindblad dynamics and other open-system dynamics provide a promising path towards efficient Gibbs sampling on quantum computers. In these proposals, the Lindbladian is obtained via an algorithmic construction akin to designing an artificial thermostat in classical Monte Carlo or molecular dynamics methods, rather than treated as an approximation to weakly coupled system-bath unitary dynamics. In this talk, we build upon the structural characterization of KMS detailed balanced Lindbladians by Fagnola and Umanita, and develop a family of efficient quantum Gibbs samplers using a finite set of jump operators (the number can be as few as one), akin to the classical Markov chain-based sampling algorithm. Compared to the existing works, our quantum Gibbs samplers have a comparable quantum simulation cost but with greater design flexibility and a much simpler implementation and error analysis. In addition, we will present an efficient preparation of low temperature Gibbs state for 2D toric code by an improved mixing time analysis.