The origin of strain-induced stabilisation of superconductivity in the lanthanum cuprates

2023/02/19 by Kevin C. Keegan, Keegan, Christopher, Mark S. Senn +5
Chemistry · Engineering · Physics and Astronomy · #FOS: Physical sciences #Inorganic Fluorides and Related Compounds #Physics of Superconductivity and Magnetism #Strongly Correlated Electrons (cond-mat.str-el) #Superconducting Materials and Applications #Superconductivity (cond-mat.supr-con)

paper · pdf · doi:10.48550/arxiv.2302.09588

openalex publication_date 2023/02/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

Suppression of superconductivity in favour of a striped phase, and its coincidence with a structural transition from a low-temperature orthorhombic (LTO) to a low-temperature tetragonal (LTT) phase, is a ubiquitous feature of hole-doped lanthanum cuprates. We study the effect of anisotropic strain on this transition using density-functional theory on both La₂CuO₄ and the recently-synthesised surrogate La₂MgO₄ to decouple electronic and structural effects. Strikingly, we find that compressive strain applied diagonally to the in-plane metal-oxygen bonds dramatically stabilises the LTO phase. Given the mutual exclusivity of 3D superconductivity and long-range static stripe order, we thereby suggest a structural mechanism for understanding experimentally-observed trends in the superconducting T_c under uniaxial pressure, and suggest principles for tuning it.

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