Irreversibility and Dephasing from Vacuum Fluctuations
| dc.creator | Buttiker, Markus | |
| dc.date | 2001-06-08 | |
| dc.date.accessioned | 2026-07-25T21:53:08Z | |
| dc.description | We investigate the role of vacuum (zero-point) fluctuations in generating decoherence in a number of simple models. First we discuss a harmonic oscillator coupled to a semi-infinite elastic string and discuss the irreversible nature of such a bath. We investigate the fluctuations in energy of the oscillator and discuss the trace the oscillator leaves in the bath. Most of the work deals with two-level systems coupled to a bosonic bath (a transmission line). For two-level systems with a Hamiltonian that commutes with the total Hamiltonian (system plus coupling plus bath) the ground state is a pure state. The energy of the system is a constant of motion. For the general case, the energy of the two-level system fluctuates, and the ground state is only partially coherent. A particular realization of such a two level system consists of a mesoscopic ring with a quantum dot coupled capacitively to a transmission line. In the presence of an Aharonov-Bohm flux this system exhibits a persistent current. This current is a measure of the coherence of the ground state. As a function of the coupling strength the ground state undergoes a crossover from a state characterized by a time-averaged persistent current which is much larger than its time-averaged mean squared fluctuations to a state characterized by a persistent current with an average amplitude that is much smaller than its mean squared fluctuations. | |
| dc.description | 27 pages, 6 figures: submitted for "Complexity from Microscopic to Macroscopic Scales: Coherence and Large Deviations", NATO ASI, Geilo, Norway, April 17-27 (2001) edited by Arne T. Skjeltorp and Tamas Vicsek, (Kluwer, Dordrecht) | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0106149 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0106149 | |
| dc.identifier | in "Complexity from Microscopic to Macroscopic Scales: Coherence and Large Deviations", edited by Arne T. Skjeltorp and Tamas Vicsek (Kluwer, Dordrecht 2002). p. 21 - 47 | |
| dc.identifier.uri | https://dspace.dare.co.zw/handle/123456789/83841 | |
| dc.subject | Mesoscale and Nanoscale Physics | |
| dc.title | Irreversibility and Dephasing from Vacuum Fluctuations | |
| dc.type | text |