Using uniaxial stress to probe the relationship between competing superconducting states in a cuprate with spin-stripe order

TL;DR

This study shows that applying uniaxial stress to a cuprate superconductor significantly suppresses spin-stripe order while enhancing three-dimensional superconductivity, indicating a close energetic balance and potential common pairing mechanisms.

Contribution

It provides new insights into how uniaxial stress influences the competition between spin-stripe order and superconductivity in cuprates, revealing their delicate energetic relationship.

Findings

Low uniaxial stress reduces spin-stripe order volume fraction.

Stress increases the onset temperature of 3D superconductivity.

Spin-stripe order and 3D superconductivity are energetically finely balanced.

Abstract

We report muon spin rotation and magnetic susceptibility experiments on in-plane stress effects on the static spin-stripe order and superconductivity in the cuprate system La2-xBaxCuO4 with x = 0.115. An extremely low uniaxial stress of 0.1 GPa induces a substantial decrease in the magnetic volume fraction and a dramatic rise in the onset of 3D superconductivity, from 10 to 32 K; however, the onset of at-least-2D superconductivity is much less sensitive to stress. These results show not only that large-volume-fraction spin-stripe order is anti-correlated with 3D superconducting (SC) coherence, but also that these states are energetically very finely balanced. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. These results strongly suggest a similar pairing mechanism for spin-stripe order, the spatially-modulated 2D and uniform 3D SC orders, imposing an important constraint on theoretical models.