Electron-like high-temperature superconductivity induced by compressive strain in La2PrNi2O7 thin films

2026/08/02 by Zhiwei Wang, Zhengjie Wang, Huiyu Wang +8 · 1 citation
Physics and Astronomy · #cond-mat.supr-con #cond-mat.mtrl-sci #cond-mat.str-el

paper · pdf

35 pages, 14 figures, 2 Tables

arxiv created 2026/08/02 · arxiv updated 2026/08/04

Abstract

The realization of high-temperature superconductivity in bilayer nickelates under epitaxial compressive strain is widely interpreted as mimicking the effects of high hydrostatic pressure. To test the equivalence of these mechanisms, we investigated a comprehensive strain continuum ranging from compressive (-2.14%) to tensile (+0.91%). Crucially, via ozone-assisted atomic-layer epitaxy, we realized high-temperature superconductivity in as-grown La2PrNi2O7 films on NdAlO3 substrates, which induce the most extreme compressive strain in this material system. Under extreme compression (-2.14%), these films exhibit a Tc_onset of 60 K, zero resistance at 33 K, and a diamagnetic response at 20 K, with magnetotransport measurements confirming a quasi-two-dimensional superconducting nature. Comparing our phase diagram with reported data reveals distinct lattice responses: unlike in pressurized crystals, the superconducting window in epitaxial films diverges significantly in the out-of-plane parameter c (or c/ap ratio) but remains consistent with the bulk regarding the in-plane parameter ap. Crucially, while superconductivity in both systems emerges from the suppression of spin-density waves (SDW), Hall measurements reveal a fundamental electronic dichotomy: optimal superconducting films are intrinsically electron-like (exhibiting a negative Hall coefficient), in stark contrast to the hole-like nature (positive Hall coefficient) of high-pressure bulk crystals and non-superconducting tensile films. Ultimately, both tuning strategies effectively modulate the underlying correlation landscape - the true driver of superconductivity - transcending the constraints of specific Fermi surface topologies. This work establishes a macroscopic platform for probing the multi-orbital physics of nickelates, offering a new dimension for investigating high-temperature superconductivity.

Citations

• Superconductivity onset above 60 K in ambient-pressure nickelate films
• Reducing the strain required for ambient-pressure superconductivity in bilayer nickelates
• Ambient-pressure superconductivity and electronic structures of engineered hybrid nickelate films
• Strain-Engineered Electronic Structure and Superconductivity in La₃Ni₂O₇ Thin Films
• Enhanced superconductivity in the compressively strained bilayer nickelate thin films by pressure
• Superconducting gap structure and bosonic mode in La2PrNi2O7 thin films at ambient pressure
• Fermi-liquid transport beyond the upper critical field in superconducting La₂PrNi₂O₇ thin films
• The effect of Carrier Doping and Thickness on the Electronic Structures of La3Ni2O7 Thin Films
• Spin correlations in La₃Ni₂O₇ thin films
• Bulk superconductivity up to 96 K in pressurized nickelate single crystals
• Absence of superconductivity and density-wave transition in ambient-pressure tetragonal La₄Ni₃O₁₀
• Superconductivity and normal-state transport in compressively strained La₂PrNi₂O₇ thin films
• Electronic structure of Ruddlesden-Popper nickelates: strain to mimic the effects pressure
• Identification of the superconductivity in bilayer nickelate La₃Ni₂O₇ upon 100 GPa
• Signatures of superconductivity near 80 K in a nickelate under high pressure
• Constructing oxide interfaces and heterostructures by atomic layer-by-layer laser molecular beam epitaxy

Cited by

• Thermodynamic phase transition, pairing symmetry and Fermi surface topology in Ruddlesden-Popper nickelate films

Related

• Superconductivity and normal-state transport in compressively strained La₂PrNi₂O₇ thin films
• Superconductivity onset above 60 K in ambient-pressure nickelate films
• Reducing the strain required for ambient-pressure superconductivity in bilayer nickelates
• Enhanced superconductivity in the compressively strained bilayer nickelate thin films by pressure
• Electronic structure of compressively strained thin film La₂PrNi₂O₇