Abstract
Abrikosov vortices contain magnetic fields and circulating currents that decay at a short range nm. However, vortices can induce Josephson phase shifts at a long range . Mechanisms of this puzzling phenomenon are not clearly understood. Here we present a systematic study of vortex-induced phase shifts in planar Josephson junctions. We make two key observations: (i) The cutoff effect: Although vortex-induced phase shift is a long-range phenomenon, it is terminated by the junction and does not persist beyond it. (ii) A linear to superlinear crossover with a rapid upturn of the phase shift occurs upon approaching a vortex to a junction. The crossover occurs at a vortex-junction distance comparable to the penetration depth. Together with theoretical and numerical analysis this allows unambiguous identification of two distinct and independent mechanisms. The short range mechanism is due to circulating vortex currents inside a superconducting electrode without involvement of magnetic fields. The long range mechanism is due to stray magnetic fields outside electrodes without circulating vortex currents. We argue that understanding of controlling parameters of vortex-induced Josephson phase shift can be used for development of novel compact cryoelectronic devices.
1 More- Received 28 August 2019
DOI:https://doi.org/10.1103/PhysRevB.100.174511
©2019 American Physical Society