dorsal/arxiv
View SchemaControl of Local Relaxation Behavior in Closed Bipartite Quantum Systems
| Authors | Harry Schmidt, Guenter Mahler |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0502181 |
| URL | https://arxiv.org/abs/quant-ph/0502181 |
| DOI | 10.1103/PhysRevE.72.016117 |
| Journal | Phys. Rev. E 72, 016117 (2005) |
Abstract
We investigate the decoherence of a spin 1/2 subsystem weakly coupled to an environment of many spins 1/2 with and without mutual coupling. The total system is closed, its state is pure and evolves under Schroedinger dynamics. Nevertheless, the considered spin typically reaches a quasi-stationary equilibrium state. Here we show that this state depends strongly on the coupling to the environment on the one hand and on the coupling within the environmental spins on the other. In particular we focus on spin star and spin ring-star geometries to investigate the effect of intra-environmental coupling on the central spin. By changing the spectrum of the environment its effect as a bath on the central spin is changed also and may even be adjustable to some degree. We find that the relaxation behavior is related to the distribution of the energy eigenstates of the total system. For each of these relaxation modes there is a dual mode for which the resulting subsystem approaches an inverted state occupation probability (negative temperature).
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"abstract": "We investigate the decoherence of a spin 1/2 subsystem weakly coupled to an\nenvironment of many spins 1/2 with and without mutual coupling. The total\nsystem is closed, its state is pure and evolves under Schroedinger dynamics.\nNevertheless, the considered spin typically reaches a quasi-stationary\nequilibrium state. Here we show that this state depends strongly on the\ncoupling to the environment on the one hand and on the coupling within the\nenvironmental spins on the other. In particular we focus on spin star and spin\nring-star geometries to investigate the effect of intra-environmental coupling\non the central spin. By changing the spectrum of the environment its effect as\na bath on the central spin is changed also and may even be adjustable to some\ndegree. We find that the relaxation behavior is related to the distribution of\nthe energy eigenstates of the total system. For each of these relaxation modes\nthere is a dual mode for which the resulting subsystem approaches an inverted\nstate occupation probability (negative temperature).",
"arxiv_id": "quant-ph/0502181",
"authors": [
"Harry Schmidt",
"Guenter Mahler"
],
"categories": [
"quant-ph",
"cond-mat.stat-mech"
],
"doi": "10.1103/PhysRevE.72.016117",
"journal_ref": "Phys. Rev. E 72, 016117 (2005)",
"title": "Control of Local Relaxation Behavior in Closed Bipartite Quantum Systems",
"url": "https://arxiv.org/abs/quant-ph/0502181"
},
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