Stochastic surrogate Hamiltonian

Journal Article · Mon Jul 21 04:00:00 EDT 2008 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.2946703· OSTI ID:21106205

Katz, Gil; Kosloff, Ronnie ^[1]; Gelman, David ^[2]; Ratner, Mark A ^[3]

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1. Fritz Haber Research Center for Molecular Dynamics, Hebrew University of Jerusalem, Jerusalem 91904 (Israel)
2. Department of Biophysics, Albert Einstein College of Medicine, New York, New York 10461 (United States)
3. Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113 (United States)

The surrogate Hamiltonian is a general scheme to simulate the many body quantum dynamics composed of a primary system coupled to a bath. The method has been based on a representative bath Hamiltonian composed of two-level systems that is able to mimic the true system-bath dynamics up to a prespecified time. The original surrogate Hamiltonian method is limited to short time dynamics since the size of the Hilbert space required to obtain convergence grows exponentially with time. By randomly swapping bath modes with a secondary thermal reservoir, the method can simulate quantum dynamics of the primary system from short times to thermal equilibrium. By averaging a small number of realizations converged values of the system observables are obtained avoiding the exponential increase in resources. The method is demonstrated for the equilibration of a molecular oscillator with a thermal bath.

• OSTI ID: 21106205
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 3 Vol. 129; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
HAMILTONIANS
HILBERT SPACE
MOLECULES
OSCILLATORS
SCHROEDINGER EQUATION
STOCHASTIC PROCESSES
THERMAL EQUILIBRIUM