0-pi Transitions in a Superconductor/Chiral Ferromagnet/Superconductor Junction induced by a Homogeneous Cycloidal Spiral

TL;DR

This paper investigates how a cycloidal spiral magnetic order in a ferromagnet affects the phase states of a superconductor-ferromagnet-superconductor Josephson junction, revealing sensitive 0-pi transitions influenced by chiral magnetic order.

Contribution

It demonstrates the impact of chiral magnetic order on Josephson junction phase transitions and introduces the role of chiral triplet pairs in these systems.

Findings

0-pi quantum phase transitions depend on spiral wave vector

Chiral magnetic order induces chiral triplet pairs

High sensitivity of junction to spiral order

Abstract

We study the pi phase in a superconductor-ferromagnet-superconductor Josephson junction, with a ferromagnet showing a cycloidal spiral spin modulation with in-plane propagation vector. Our results reveal a high sensitivity of the junction to the spiral order and indicate the presence of 0-pi quantum phase transitions as function of the spiral wave vector. We find that the chiral magnetic order introduces chiral superconducting triplet pairs that strongly influence the physics in such Josephson junctions, with potential applications in nanoelectronics and spintronics.