Manipulating fractional Shapiro steps in twisted cuprate Josephson junctions.

ABSTRACT: High-quality Josephson junctions made of twisted cuprate superconductors offer unprecedented opportunities in addressing fundamental problems and realizing next-generation superconducting devices at relatively high temperatures. Whether or not the twisted cuprates possess high-temperature topological superconductivity remains an outstanding issue. Here, we tackle this problem via an in-depth study of the key predicted feature-half-integer Shapiro steps. We show that half-integer Shapiro steps do occur in samples at a twist angle of 45°, but they are unstable, with thermal cycling. Interestingly, fractional steps can be introduced by training the sample with a small magnetic field or annealing with a large electrical current, attesting to a tunable current-phase relation (CPR) in twisted cu

SUBMITTER: Zhu Y 

PROVIDER: S-EPMC12917811 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature