Nanoscopic coexistence of magnetism and superconductivity in YBa2Cu3O6+x detected by MuSR

TL;DR

This study reveals the microscopic coexistence of short-range antiferromagnetic order and superconductivity in YBa2Cu3O6+x, showing that magnetic stripes are embedded within the superconducting phase, with implications for understanding high-temperature superconductivity.

Contribution

It provides direct MuSR evidence of microscopic coexistence of magnetism and superconductivity in YBa2Cu3O6+x, and maps the phase diagram highlighting minimal interference between these states.

Findings

Coexistence of AF magnetism and superconductivity below ~10 K.

Most muons detect local AF fields even in superconducting volume.

Phase diagram illustrating minimal interference between magnetism and superconductivity.

Abstract

We performed zero and transverse field MuSR experiments on a large number of YBa2Cu3O6+x samples. We detect coexistence of antiferro-type (AF) short range magnetism with superconductivity below T_f~10 K in compositions 0.37<x<0.39. Most muons experience local AF fields, even when SQUID detects a full SC volume fraction, which points to a local minimal interference organization of short AF stripes embedded in the superconductor. A detailed phase diagram is produced and the consequences of the minimal interference are discussed.