Reentrance effect in macroscopic quantum tunneling and non-adiabatic Josephson dynamics in d-wave junctions

TL;DR

This paper presents a theoretical study of non-adiabatic Josephson dynamics in d-wave superconductor junctions, revealing a reentrance effect in quantum tunneling transitions linked to midgap states, with implications for experimental observations.

Contribution

It introduces a new theoretical framework for understanding non-adiabatic Josephson dynamics in unconventional superconductors, highlighting the reentrance effect and resonant interactions with midgap states.

Findings

Reentrance effect in transition between thermal activation and quantum tunneling.

Connection of reentrance phenomenon to experimental observations.

Resonant interaction with midgap states affecting nonlinear dynamics.

Abstract

We develop a theoretical description of non-adiabatic Josephson dynamics in superconducting junctions containing low energy quasiparticles. Within this approach we investigate the effects of midgap states in junctions of unconventional d-wave superconductors. We identify a reentrance effect in the transition between thermal activation and macroscopic quantum tunneling, and connect this phenomenon to the experimental observations in Phys. Rev. Lett. 94, 087003 (2005). It is also shown that nonlinear Josephson dynamics can be defined by resonant interaction with midgap states reminiscent to nonlinear optical phenomena in media of two-level atoms.