Quantum Decoherences in Open Systems
碩士 === 國立成功大學 === 物理學系碩博士班 === 96 === In this thesis we explore decoherence in open quantum systems. We approach this problem using Feynman-Vernon’s influence functional theory in two very distinct systems. We consider first a wave packet of a particle in a harmonic trap interacting with an environm...
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| Format: | Others |
| Language: | en_US |
| Online Access: | http://ndltd.ncl.edu.tw/handle/48798334550943318620 |
| Summary: | 碩士 === 國立成功大學 === 物理學系碩博士班 === 96 === In this thesis we explore decoherence in open quantum systems. We approach this problem using Feynman-Vernon’s influence functional theory in two very distinct systems. We consider first a wave packet of a particle in a harmonic trap interacting with an environment with discrete
spectra where the reduced dynamics of the wave packet is studied. Instability due to the interaction between the system and its quantum environment is investigated and Markovian to non-Markovian transition is discussed. We then extend the theory to the fermion coherent state representation to study the decoherent dynamics of electrons in a double quantum dot under the influence of electron reservoirs connected to the dots. There we derived an exact master equation for arbitrary spectral densities for dot-lead tunneling via the stationary path
equations which fully manifests the complex non-Markovian charge dynamics. Real time fluctuations of the double dot parameters are explored and decoherence are closely analyzed based on our exact solutions from Markovian to non-Markovian regimes.
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