Tuning from failed superconductor to failed insulator with magnetic field

TL;DR

This study explores how high magnetic fields suppress superconductivity in cuprates, revealing phases like reentrant 2D superconductivity and an ultra-quantum metal, supporting theories of charge segregation and pairing mechanisms.

Contribution

It provides experimental evidence linking charge stripes and magnetic fields to phases in high-temperature superconductors, advancing understanding of their electron pairing mechanisms.

Findings

Suppression of 3D superconductivity with magnetic field

Observation of reentrant 2D superconductivity

Identification of an ultra-quantum metal phase

Abstract

Do charge modulations compete with electron pairing in high-temperature copper-oxide superconductors? We investigated this question by suppressing superconductivity in a stripe-ordered cuprate compound at low temperature with high magnetic fields. With increasing field, loss of three-dimensional superconducting order is followed by reentrant two-dimensional superconductivity and then an ultra-quantum metal phase. Circumstantial evidence suggests that the latter state is bosonic and associated with the charge stripes. These results provide experimental support to the theoretical perspective that local segregation of doped holes and antiferromagnetic spin correlations underlies the electron-pairing mechanism in cuprates.