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Interaction of a two‐level cyclic XY n ‐spin model with a two‐mode cavity field in off‐resonant states
Author(s) -
Grinberg Horacio
Publication year - 2007
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.21472
Subject(s) - excited state , physics , population inversion , population , quantum mechanics , photon , coherent states , operator (biology) , time evolution , perturbation (astronomy) , rotating wave approximation , quantum electrodynamics , atomic physics , quantum , chemistry , laser , biochemistry , demography , repressor , sociology , transcription factor , gene
The interaction of the XY n ‐spin cyclic model with a two‐mode cavity field in the rotating‐wave approximation is investigated in the framework of a generalized Jaynes–Cummings two‐level system consisting of the vacuum state and a thermally averaged manifold of excited sates. Computation of the energy of this manifold allows this interaction to be examined in off‐resonant states. Time evolution of the population inversion, photon distribution, and temperature distribution for an excited initial state are computed via second‐ and third‐order perturbation expansion of the time evolution operator matrix elements for the excited and ground states, respectively and for an ideal squeezed initial coherent state of the cavity field. It was assumed that the two modes have initially the same photon distribution. The pattern of the spin population inversion appears as a manifestation of multiple and complicated inerferences, which is mathematically reflected in a double discrete summation that appears in the calculation of the dynamics. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008