Renyi free energy and variational approximations to thermal states

Article

关键词: MATRIX RENORMALIZATION-GROUP;    INFORMATION-THEORY;    PRODUCT STATES;    SPIN CHAIN;   

DOI  :  10.1103/PhysRevB.103.205128

来源: SCIE

【 摘 要 】

We propose the construction of thermodynamic ensembles that minimize the Renyi free energy, as an alternative to Gibbs states. For large systems, the local properties of these Renyi ensembles coincide with those of thermal equilibrium and they can be used as approximations to thermal states. We provide algorithms to find tensor network approximations to the 2-Renyi ensemble. In particular, a matrix-product-state representation can be found by using gradient-based optimization on Riemannian manifolds or via a nonlinear evolution which yields the desired state as a fixed point. We analyze the performance of the algorithms and the properties of the ensembles on one-dimensional spin chains.

【 授权许可】

Free