Odd-frequency Pairing in Conventional Josephson Junctions

TL;DR

This paper theoretically demonstrates the emergence of odd-frequency pairing in conventional Josephson junctions and links it to measurable effects like spin-susceptibility changes, highlighting its significance in superconducting physics.

Contribution

It introduces a simple model showing odd-frequency pairing in Josephson junctions and connects it to spin-susceptibility, revealing new insights into conventional superconducting systems.

Findings

Odd-frequency pair amplitudes appear when Josephson current flows.

Spin-susceptibility is suppressed with dominant odd-frequency pairing.

Odd-frequency pairing influences conventional superconducting properties.

Abstract

Using a simple theoretical model, we demonstrate the emergence of odd-frequency pair amplitudes in conventional Josephson junctions both in the absence of a voltage (DC effect) and in the presence of a finite voltage (AC effect). In both cases, we find that odd-frequency interlead pairing emerges whenever a Josephson current is expected to flow. Additionally, we show that the interlead spin-susceptibility is directly influenced by the presence of the odd-frequency pair amplitudes. Specifically, we find that the spin-susceptibility is suppressed when the odd-frequency component is the largest. By establishing a novel link between the physics of Josephson junctions and odd-frequency pairing, this work demonstrates the importance of odd-frequency pairing for understanding conventional superconducting systems.