Critical currents in conventional Josephson junctions with grain boundaries
Abstract
It has been hypothesized that the variation of the critical currents in Nb/Al–AlOx/Nb junctions is due to, among other effects, the presence of grain boundaries in the system. Motivated by this, we examine the effect of grain boundaries on the critical current of a Josephson junction. We assume that the hopping amplitudes are dependent on the interatomic distance and derive a physically realistic model of distance-dependent hopping amplitudes. We find that the presence of a grain boundary and associated disorder is responsible for a very large drop in the critical current relative to a clean system. We also find that when a tunnel barrier is present, grain boundaries cause substantial variations in the critical currents due to the disordered hoppings near the tunnel barrier. We discuss the applicability of these results to Josephson junctions presently intended for use in superconducting electronics applications.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 11, 2021
- Source ID
- 10.1063/5.0060784
Entities
People
- Andreas Kreisel
- E. Patrick
- Laetitia P. Bettmann
- Mark E. Law
- Miguel Antonio Sulangi
- Nimesh Pokhrel
- P. J. Hirschfeld
- Thomas Weingartner
Organizations
- Division of Materials Research
- Intelligence Advanced Research Projects Activity
- Leipzig University
- University of Florida