Field-induced electronic phase separation in a cuprate high temperature superconductor

Abstract

We present a combined neutron diffraction (ND) and high-field muon spin rotation (µSR) study of the magnetic and superconducting phases of the high-temperature superconductor La1.94Sr0.06CuO4+y (Tc = 38 K). We observe a linear dependence of the ND signal from the modulated antiferromagnetic order (m-AFM) on the applied field. The magnetic volume fraction measured with µSR increases linearly from 0% to ∼40% with applied magnetic field up to 8 T. This allows us to conclude, in contrast to earlier field-dependent neutron diffraction studies, that the long-range m-AFM regions are induced by an applied field, and that their ordered magnetic moment remains constant.