φ-state and inverted Fraunhofer pattern in nonaligned Josephson junctions

Mohammad Alidoust; Jacob Linder

doi:10.1103/PhysRevB.87.060503

← Back to search

φ-state and inverted Fraunhofer pattern in nonaligned Josephson junctions

Mohammad Alidoust, Jacob Linder

DOI 10.1103/PhysRevB.87.060503 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

A generic nonaligned Josephson junction in the presence of an external magnetic field is theoretically considered and an unusual flux-dependent current-phase relation (CPR) is revealed. We explain the origin of the anomalous CPR via the current density flow induced by the external field within a two-dimensional quasiclassical Keldysh-Usadel framework. In particular, it is demonstrated that nonaligned Josephson junctions can be utilized to obtain a ground state other than 0 and π, corresponding to a so-called φ junction, which is tunable via the external magnetic flux. Furthermore, we show that the standard Fraunhofer central peak of the critical supercurrent may be inverted into a local minimum solely due to geometrical factors in planar junctions. This yields good consistency with a recent experimental measurement displaying such type of puzzling feature [Keizer et al., Nature (London) 439, 825 (2006)].