Magnetotransport signatures of spin-orbit coupling in high-temperature cuprate superconductors

TL;DR

This study uncovers strong spin-orbit coupling effects in high-temperature cuprate superconductors, demonstrated by large anisotropic magnetoresistance and planar Hall effect, suggesting new avenues for spintronics in these materials.

Contribution

It reveals significant spin-orbit coupling in cuprates through magnetotransport measurements, challenging the prior assumption of negligible spin-orbit interactions in these materials.

Findings

Observation of large anisotropic magnetoresistance near superconducting transition

Detection of a pronounced planar Hall effect without ferromagnetic proximity

Evidence of spin-orbit-driven quasiparticle transport in cuprates

Abstract

Spin transport in superconductors offers a compelling platform to merge the dissipationless nature of superconductivity with the functional promise of spin-based electronics. A significant challenge in achieving spin polarisation in conventional superconductors stems from the singlet state of Cooper pairs, which exhibit no net spin. The generation of spin-polarised carriers, quasiparticles, or triplet pairs in superconductors has predominantly been realised in hybrid superconductor/ferromagnet systems through proximity-induced spin polarisation. Historically, cuprate superconductors have been characterised by strong electronic correlations but negligible spin-orbit coupling. Here, we report exceptionally large anisotropic magnetoresistance and a pronounced planar Hall effect arising near the superconducting phase transition in the prototypical high-temperature cuprate superconductor YBa2Cu3O7-x without using a proximity ferromagnet. These effects, unprecedented in centrosymmetric cuprates, emerge from spin-polarised quasiparticle transport mediated by strong spin-orbit coupling. By systematically tuning magnetic field strength, orientation, temperature, and doping, we show clear evidence of spin-orbit-driven transport phenomena in a material class long thought to lack such interactions. Our findings reveal an unexpected spin-orbit landscape in cuprates and open a route to engineer spintronic functionalities in high-temperature superconductors.