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Title
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Energy transfer using unitary transformations
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Author
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Abstract
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| We study the unitary time evolution of a simple quantum Hamiltonian describing two harmonic oscillators coupled via a three-level system. The latter acts as an engine transferring energy from one oscillator to the other and is driven in a cyclic manner by time-dependent external fields. The S-matrix (scattering matrix) of the cycle is obtained in analytic form. The total number of quanta contained in the system is a conserved quantity. As a consequence, the spectrum of the S-matrix is purely discrete, and the evolution of the system is quasi-periodic. The explicit knowledge of the S-matrix makes it possible to do accurate numerical evaluations of the time-dependent wave function. They confirm the quasi-periodic behavior. In particular, the energy flows back and forth between the two oscillators in a quasi-periodic manner. |
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Language
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English
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Source (journal)
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Entropy: an international and interdisciplinary journal of entropy and information studies. - -
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Publication
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2013
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ISSN
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1099-4300
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DOI
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10.3390/E15125121
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Volume/pages
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15
:12
(2013)
, p. 5121-5143
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ISI
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000330339700002
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Full text (Publisher's DOI)
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Full text (open access)
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