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Updated: Oct 29, 2025

Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
Semiclassical description of nuclear dynamics moving through complex-valued single avoided crossings of two
1Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Abstract:
The standard fewest-switches surface hopping (FSSH) approach fails to model nonadiabatic dynamics when the electronic Hamiltonian is complex-valued and there are multiple nuclear dimensions; FSSH does not include geometric magnetic effects and does not have access to a gauge independent direction for momentum rescaling. In this paper, for the case of a Hamiltonian with two electronic states, we propose an extension of Tully's FSSH algorithm, which includes geometric magnetic forces and, through diabatization, establishes a well-defined rescaling direction. When combined with a decoherence correction, our new algorithm shows satisfying results for a model set of two-dimensional single avoided crossings.
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