Non-Hermitian wave packet approximation of Bloch optical equations

Journal Article · Mon Jan 14 04:00:00 EST 2013 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4774056· OSTI ID:22105336

Charron, Eric ^[1]; Sukharev, Maxim ^[2]

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1. Universite Paris-Sud, Institut des Sciences Moleculaires d'Orsay, ISMO, CNRS, F-91405 Orsay (France)
2. Department of Applied Sciences and Mathematics, Arizona State University, Mesa, Arizona 85212 (United States)

We introduce a non-Hermitian approximation of Bloch optical equations. This approximation provides a complete description of the excitation, relaxation, and decoherence dynamics of ensembles of coupled quantum systems in weak laser fields, taking into account collective effects and dephasing. In the proposed method, one propagates the wave function of the system instead of a complete density matrix. Relaxation and dephasing are taken into account via automatically adjusted time-dependent gain and decay rates. As an application, we compute the numerical wave packet solution of a time-dependent non-Hermitian Schroedinger equation describing the interaction of electromagnetic radiation with a quantum nano-structure, and compare the calculated transmission, reflection, and absorption spectra with those obtained from the numerical solution of the Liouville-von Neumann equation. It is shown that the proposed wave packet scheme is significantly faster than the propagation of the full density matrix while maintaining small error. We provide the key ingredients for easy-to-use implementation of the proposed scheme and identify the limits and error scaling of this approximation.

• OSTI ID: 22105336
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 2 Vol. 138; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
77 NANOSCIENCE AND NANOTECHNOLOGY
ABSORPTION SPECTRA
APPROXIMATIONS
DENSITY MATRIX
INTERACTIONS
LASER RADIATION
NANOSTRUCTURES
NUMERICAL ANALYSIS
NUMERICAL SOLUTION
SCHROEDINGER EQUATION
TIME DEPENDENCE
ULTRAVIOLET SPECTRA
WAVE FUNCTIONS
WAVE PACKETS