Efficiency of free-energy calculations of spin lattices by spectral quantum algorithms

Journal Article · Sat Mar 01 00:00:00 EST 2003 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.67.032311· OSTI ID:20633826

Master, Cyrus P; Yamaguchi, Fumiko ^[1]; Yamamoto, Yoshihisa ^[1]

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1. Quantum Entanglement Project, ICORP, JST, Stanford University, Stanford, California 94305-4085 (United States)

Ensemble quantum algorithms are well suited to calculate estimates of the energy spectra for spin-lattice systems. Based on the phase estimation algorithm, these algorithms efficiently estimate discrete Fourier coefficients of the density of states. Their efficiency in calculating the free energy per spin of general spin lattices to bounded error is examined. We find that the number of Fourier components required to bound the error in the free energy due to the broadening of the density of states scales polynomially with the number of spins in the lattice. However, the precision with which the Fourier components must be calculated is found to be an exponential function of the system size.

• OSTI ID: 20633826
• Journal Information: Physical Review. A, Vol. 67, Issue 3; Other Information: DOI: 10.1103/PhysRevA.67.032311; (c) 2003 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ACCURACY
ALGORITHMS
DENSITY
EFFICIENCY
ENERGY SPECTRA
ERRORS
FREE ENERGY
LATTICE FIELD THEORY
SPIN