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

Journal Article · Fri Nov 27 00:00:00 EST 2009 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.103.220502· OSTI ID:21370861

Poulin, David ^[1]; Wocjan, Pawel ^[2]

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1. Departement de Physique, Universite de Sherbrooke, Quebec, J1K 2R1 (Canada)
2. School of Electrical Engineering and Computer Science, University of Central Florida, Florida 32816-2362 (United States)

We present a quantum algorithm to prepare the thermal Gibbs state of interacting quantum systems. This algorithm sets a universal upper bound D{sup {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.

• OSTI ID: 21370861
• Journal Information: Physical Review Letters, Vol. 103, Issue 22; Other Information: DOI: 10.1103/PhysRevLett.103.220502; (c) 2009 The American Physical Society; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALGORITHMS
FREE ENERGY
HILBERT SPACE
PARTITION FUNCTIONS
QUANTUM COMPUTERS
QUANTUM MECHANICS
THERMALIZATION
BANACH SPACE
COMPUTERS
ENERGY
FUNCTIONS
MATHEMATICAL LOGIC
MATHEMATICAL SPACE
MECHANICS
PHYSICAL PROPERTIES
SLOWING-DOWN
SPACE
THERMODYNAMIC PROPERTIES