Anomalous temperature dependence of the supercurrent through a chaotic Josephson junction
| dc.creator | Brouwer, P. W. | |
| dc.creator | Beenakker, C. W. J. | |
| dc.date | 1996-11-21 | |
| dc.date | 2004-08-27 | |
| dc.date.accessioned | 2026-07-07T09:02:34Z | |
| dc.date.available | 2026-07-07T09:02:34Z | |
| dc.description | We calculate the supercurrent through a Josephson junction consisting of a phase-coherent metal particle (quantum dot), weakly coupled to two superconductors. The classical motion in the quantum dot is assumed to be chaotic on time scales greater than the ergodic time $τ_{erg}$, which itself is much smaller than the mean dwell time $τ_{dwell}$. The excitation spectrum of the Josephson junction has a gap $E_{gap}$, which can be less than the gap $Δ$ in the bulk superconductors. The average supercurrent is computed in the ergodic regime $τ_{erg} \ll \hbar/Δ$, using random-matrix theory, and in the non-ergodic regime $τ_{erg} \gg \hbar/Δ$, using a semiclassical relation between the supercurrent and dwell-time distribution. In contrast to conventional Josephson junctions, raising the temperature above the excitation gap does not necessarily lead to an exponential suppression of the supercurrent. Instead, we find a temperature regime between $E_{gap}$ and $Δ$ where the supercurrent decreases logarithmically with temperature. This anomalously weak temperature dependence is caused by long-range correlations in the excitation spectrum, which extend over an energy range $\hbar/τ_{erg}$ greater than $E_{gap} \simeq \hbar/τ_{dwell}$. A similar logarithmic temperature dependence of the supercurrent was discovered by Aslamazov, Larkin, and Ovchinnikov, in a Josephson junction consisting of a disordered metal between two tunnel barriers. | |
| dc.description | 14 pages with 2 figures; the revision corrects the published version in Eqs. 8, 15, and 21d (with thanks to Marlies Goorden) | |
| dc.identifier | https://arxiv.org/abs/cond-mat/9611162 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/9611162 | |
| dc.identifier | Chaos, Solitons & Fractals 8, 1249 (1997) | |
| dc.identifier | doi:10.1016/S0960-0779(97)00018-0 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/148679 | |
| dc.subject | Mesoscale and Nanoscale Physics | |
| dc.title | Anomalous temperature dependence of the supercurrent through a chaotic Josephson junction | |
| dc.type | text |