Entropy | |
Energy Transfer Using Unitary Transformations | |
Winny O’Kelly de Galway1  | |
[1] Institute for Theoretical Physics, KU Leuven, Leuven B-3001, Belgium; E-Mail: | |
关键词: quantum stirring; S-matrix; driven quantum system; three-level system; | |
DOI : 10.3390/e15125121 | |
来源: mdpi | |
【 摘 要 】
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.
【 授权许可】
CC BY
© 2013 by the authors; licensee MDPI, Basel, Switzerland.
【 预 览 】
Files | Size | Format | View |
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RO202003190031190ZK.pdf | 267KB | download |