Phase diagram of geometric d-wave superconductor Josephson junctions

TL;DR

This paper investigates how the phase difference in d-wave superconductor Josephson junctions varies with geometry and temperature, revealing intrinsic 0 to pi transitions through microscopic theory.

Contribution

It provides a microscopic derivation of free energy relations and phase diagrams for geometric d-wave Josephson junctions, highlighting intrinsic phase differences.

Findings

Phase differences depend on geometry and temperature.

Transitions between 0 and pi states are driven by geometric parameters.

Phase diagrams illustrate the conditions for different phase states.

Abstract

We show that a constriction-type Josephson junction realized by an epitactic thin film of a d-wave superconductor with an appropriate boundary geometry exhibits intrinsic phase differences between 0 and pi depending on geometric parameters and temperature. Based on microscopic Eilenberger theory, we provide a general derivation of the relation between the change of the free energy of the junction and the current-phase relation. From the change of the free energy, we calculate phase diagrams and discuss transitions driven by geometric parameters and temperature.