Preparing Thermal States of Quantum Systems by Dimension Reduction

Journal Article · Fri Oct 22 00:00:00 EDT 2010 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.105.170405· OSTI ID:21467030

Bilgin, Ersen; Boixo, Sergio ^[1]

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1. Institute of Quantum Information, California Institute of Technology, Pasadena, California, 91125 (United States)

We present an algorithm that prepares thermal Gibbs states of one dimensional quantum systems on a quantum computer without any memory overhead, and in a time significantly shorter than other known alternatives. Specifically, the time complexity is dominated by the quantity N{sup ||h||}/{sup T}, where N is the size of the system, || h || is a bound on the operator norm of the local terms of the Hamiltonian (coupling energy), and T is the temperature. Given other results on the complexity of thermalization, this overall scaling is likely optimal. For higher dimensions, our algorithm lowers the known scaling of the time complexity with the dimension of the system by one.

• OSTI ID: 21467030
• Journal Information: Physical Review Letters, Vol. 105, Issue 17; Other Information: DOI: 10.1103/PhysRevLett.105.170405; (c) 2010 American Institute of Physics; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ALGORITHMS
COMPACTIFICATION
COUPLING
HAMILTONIANS
ONE-DIMENSIONAL CALCULATIONS
QUANTUM COMPUTERS
QUANTUM MECHANICS
QUANTUM STATES
THERMALIZATION
COMPUTERS
MATHEMATICAL LOGIC
MATHEMATICAL OPERATORS
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