We study the phenomenon of macroscopic quantum tunneling (MQT) in a finite-size Josephson junction (JJ) with an externally applied magnetic field. As is well known, the problem of MQT in a pointlike JJ is reduced to the study of the under-barrier motion of a quantum particle in the washboard potential. In the case of a finite-size JJ placed in magnetic field, this problem is considerably more complex since, besides the phase, the potential itself depends on space variables. We find the general expressions both for the crossover temperature To between thermally activated and MQT regimes and the escape time tau(esc). It turns out that in the proximity of particular values of magnetic field, the crossover temperature can vary nonmonotonically.

Effect of magnetic field on macroscopic quantum tunneling escape time in small Josephson junctions

2008

Abstract

We study the phenomenon of macroscopic quantum tunneling (MQT) in a finite-size Josephson junction (JJ) with an externally applied magnetic field. As is well known, the problem of MQT in a pointlike JJ is reduced to the study of the under-barrier motion of a quantum particle in the washboard potential. In the case of a finite-size JJ placed in magnetic field, this problem is considerably more complex since, besides the phase, the potential itself depends on space variables. We find the general expressions both for the crossover temperature To between thermally activated and MQT regimes and the escape time tau(esc). It turns out that in the proximity of particular values of magnetic field, the crossover temperature can vary nonmonotonically.
2008
INFM
VOLTAGE
DECAY
SUPERCONDUCTORS
STATE
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14243/119943
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact