Sampling from the Thermal Quantum Gibbs State and Evaluating Partition Functions with a Quantum Computer

    Authors

    D. Poulin;P. Wocjan

    Abbreviated Journal Title

    Phys. Rev. Lett.

    Keywords

    Physics, Multidisciplinary

    Abstract

    We present a quantum algorithm to prepare the thermal Gibbs state of interacting quantum systems. This algorithm sets a universal upper bound D-alpha on the thermalization time of a quantum system, where D is the system's Hilbert space dimension and alpha < = 1/2 is proportional to the Helmholtz free energy density. We also derive an algorithm to evaluate the partition function of a quantum system in a time proportional to the system's thermalization time and inversely proportional to the targeted accuracy squared.

    Journal Title

    Physical Review Letters

    Volume

    103

    Issue/Number

    22

    Publication Date

    1-1-2009

    Document Type

    Article

    Language

    English

    First Page

    4

    WOS Identifier

    WOS:000272182000003

    ISSN

    0031-9007

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