Source capture
Authors D. Sanchez-Manzano, V. Humbert, D. Zhang, A. Gutiérrez-Llorente, M. Bibes, J. Santamaria L. Iglesias, Javier E. Villegas
arXiv / Publisher https://arxiv.org/abs/2410.14341
PDF https://arxiv.org/pdf/2410.14341
Relevance score 5.149
Primary category cond-mat.supr-con
Published 2026-03-12
Research paradigm Experimental
Sample form Thin Film

Summary

This study investigates the dimensionality of the superconducting state in infinite-layer nickel oxides by mapping the vortex phase diagram of superconducting Pr0.8Sr0.2NiO2 thin films from multiple perspectives. Experimental results reveal that low-disorder films exhibit a quasi-two-dimensional vortex liquid-to-glass transition, while increasing disorder drives the system into a pure two-dimensional state. This finding indicates that pure two-dimensionality is not an intrinsic property but an extrinsic phenomenon caused by the decoupling of NiO2 layers due to enhanced disorder. The work establishes disorder as a key tuning parameter for superconductivity in infinite-layer nickel oxides and identifies that disorder primarily resides within the NiO2 layers, offering two fundamental insights for understanding this class of materials.

Materials

Methods

Keywords

  • vortex matter dimensionality
  • vortex glass transition
  • quasi 2d to 2d crossover
  • disorder driven decoupling
  • nio2 plane superconductivity
  • pancake vortices
  • pauli limited superconductivity

Highlights

  • For low-disorder films, the vortex glass transition temperature Tg is finite and critical exponents match q2D theory; for higher disorder, Tg=0 K and pure 2D scaling applies.
  • The vortex length scale shortens with disorder, becoming comparable to the interplane distance.
  • The results suggest that superconductivity is confined to NiO2 planes with weak interplane coupling, and disorder enhances decoupling.

Conclusions

  • Superconducting Pr0.8Sr0.2NiO2 thin films with low disorder exhibit a vortex liquid-to-glass transition of a quasi-two-dimensional nature.
  • Increasing disorder drives a crossover into a pure 2D state.
  • This demonstrates that pure bidimensionality is an extrinsic property, resulting from the decoupling of NiO2 planes due to enhanced disorder.
  • Disorder is a key control parameter of superconductivity in IL nickelates and suggests that it resides within the NiO2 planes.

Main claims

  • Low-disorder films exhibit a quasi-two-dimensional vortex liquid-to-glass transition.
    • Evidence: Abstract,Full text: Low-disorder films exhibit a vortex liquid-to-glass transition of a quasi-2D nature.
  • Increasing disorder drives a crossover into a pure 2D state.
    • Evidence: Abstract,Full text: increasing disorder drives a crossover into a pure 2D state.
  • Pure bidimensionality is an extrinsic property resulting from decoupling of NiO2 planes due to enhanced disorder.
    • Evidence: Abstract,Full text: pure bidimensionality is an extrinsic property, resulting from the decoupling of NiO2 planes due to enhanced disorder.

Workflow

  • sample_preparation
    • Materials: Pr0.8Sr0.2NiO2; SrTiO3 substrate; STO capping layer; Al overlayer
    • Methods: pulsed laser deposition; ex situ CaH2 reduction; Al-assisted reduction
  • transport_measurement
    • Methods: resistivity measurements; V-I measurements
    • Observations: vortex liquid-to-glass transition
  • vortex_phase_analysis
    • Methods: Arrhenius analysis; vortex-glass scaling theory
    • Observations: quasi-2D behavior in low-disorder films; pure 2D behavior in high-disorder films
  • interpretation — Disorder drives a dimensional crossover from quasi-2D to pure 2D vortex behavior.