Angular variation of the magnetoresistance of the superconducting ferromagnet UCoGe

TL;DR

This study investigates the angular dependence of magnetoresistance in the superconducting ferromagnet UCoGe, revealing a field-induced phenomenon with uniaxial anisotropy and pressure-dependent behavior, contributing to understanding its complex magnetic and superconducting properties.

Contribution

It provides the first detailed analysis of angular variation and pressure effects on magnetoresistance in UCoGe, highlighting a field-induced polarization change and anisotropic behavior.

Findings

Pronounced structure at B* = 8.5 T with uniaxial anisotropy.

B* increases to 12.8 T under 1.0 GPa pressure.

Unusual S-shaped Bc2(T) curve for field along the b-axis.

Abstract

We report a magnetoresistance study of the superconducting ferromagnet UCoGe. The data, taken on single-crystalline samples, show a pronounced structure at $B^* = 8.5$~T for a field applied along the ordered moment $m_0$. Angle dependent measurements reveal this field-induced phenomenon has an uniaxial anisotropy. Magnetoresistance measurements under pressure show a rapid increase of $B^*$ to 12.8~T at 1.0~GPa. We discuss $B^*$ in terms of a field induced polarization change. Upper critical field measurements corroborate the unusual S-shaped $B_{c2}(T)$-curve for a field along the $b$-axis of the orthorhombic unit cell.