DC Current Driven Critical Current Variation in Sr2RuO4-Ru Junction Proved by Local Transport Measurements

TL;DR

This study reveals that dc currents influence chiral p-wave domain walls in Sr2RuO4, causing hysteresis in local transport measurements, which advances understanding of its unconventional superconducting properties.

Contribution

It demonstrates that dc current, not magnetic field, drives domain wall movement in Sr2RuO4, providing new evidence for chiral p-wave superconductivity.

Findings

DC current affects hysteresis in voltage-current characteristics.

Domain walls shift due to dc current, not magnetic fields.

Critical current paths are altered by domain wall movement.

Abstract

To search for new evidence of the chiral p-wave superconducting domain in Sr2RuO4, we investigated the unconventional local transport characteristics of a microfabricated Sr2RuO4-Ru eutectic junction. We found that the anomalous hysteresis in voltage-current characteristics [as reported in H. Kambara et al.: Phys. Rev. Lett. 101 (2008) 267003.] is strongly affected by dc currents, but not by magnetic fields. This suggests that dc current acts as a driving force to move chiral p-wave domain walls; a domain wall trapped at a pinning potential is forced to shift to the next stable position, thereby forming a larger critical current path and resulting in the anomalous hysteresis.