Abstract
Even at zero temperature dissipation reduces quantum fluctuations and tends to localize particles. A notable exception is the nonlinear dissipation due to quasiparticle tunneling in a Josephson junction. It is well known that quasiparticle dissipation does not suppress tunneling of the superconducting phase difference between next-nearest metastable phase states even though tunneling to the nearest phase state is suppressed. The reason is that the dissipative action admits an instanton solution, the so-called Korshunov instanton. Here, we analyze this model at elevated bias current . We find that besides the known regime where the logarithm of the tunneling rate scales as there is a novel regime with a scaling . We argue that the increased tunneling rate that derives from the elevated bias current is favorable for experimental verification of the Korshunov instantons.
- Received 8 May 2017
- Revised 12 September 2017
DOI:https://doi.org/10.1103/PhysRevB.96.125433
©2017 American Physical Society