Point-contact Andreev reflection spectroscopy of layered superconductors with device-integrated diamond anvil cells

Abstract

Superconductors that can be mechanically exfoliated are an interesting platform for exploring superconducting properties tuned by layer thickness. These layered superconductors are also expected to exhibit sensitivity to applied pressure. While pressure has been demonstrated to be an effective way of tuning bulk superconductors, analogous studies on superconducting thin flakes have been limited due to technical challenges. In particular, spectroscopic measurements under pressure remain insufficiently explored. In this work, we functionalized the diamond anvil cell technique for point-contact Andreev reflection spectroscopy (PCAR) measurement on thin-flake materials under pressure, offering the opportunity to obtain spectroscopic information on superconductivity. To validate the feasibility of this method, we have conducted PCAR measurements on iron-selenide thin flakes to extract temperature-dependent superconducting gap values under ambient and high pressure. Combine with the proven magnetotransport capability, our method provides a conceptually simple tool for a detailed examination of thin-flake superconductors under pressure.

arXiv comment8 pages, 7 figures, Editor's Pick

References in corpus (33)

• Superconductivity in Weyl Semimetal Candidate MoTe2
• Superconductivity at 27 K in tetragonal FeSe under high pressure
• Pressure evolution of low-temperature crystal structure and bonding of 37 K $T_c$ FeSe superconductor
• Highly crystalline 2D superconductors
• Superconductivity up to 29 K in SrFe2As2 and BaFe2As2 at high pressures
• Double superconducting dome and triple enhancement of Tc in the kagome superconductor CsV3Sb5 under high pressure
• Pressure-driven dome-shaped superconductivity and electronic structural evolution in tungsten ditelluride
• Field-induced superconducting phase of FeSe in the BCS-BEC cross-over
• Discovery of Orbital-Selective Cooper Pairing in FeSe
• Superconductivity emerging from suppressed large magnetoresistant state in WTe2
• Unusual competition of superconductivity and charge-density-wave state in a compressed topological kagome metal
• Dome-shaped magnetic order competing with high-temperature superconductivity at high pressures in FeSe
• The role of critical current on point contact Andreev Reflection spectrum between a normal metal and a superconductor
• Precise Pressure Dependence of the Superconducting Transition Temperature of FeSe: Resistivity and ^77Se--NMR Study
• Evolution of two-gap behavior of the superconductor FeSe_1-x
• Pressure-induced antiferromagnetic transition and phase diagram in FeSe
• Anticorrelation between polar lattice instability and superconductivity in the Weyl semimetal candidate MoTe2
• Evidence for time-reversal symmetry breaking of the superconducting state near twin-boundary interfaces in FeSe
• Nodeless superconductivity in kagome metal CsV${}_3$Sb${}_5$ with and without time reversal symmetry breaking
• Orbital Origin of Extremely Anisotropic Superconducting Gap in Nematic Phase of FeSe Superconductor
• Superconducting gap structure of FeSe
• Mechanical control of crystal symmetry and superconductivity in Weyl semimetal MoTe${}_2$
• Thermal Conductivity of the Iron-Based Superconductor FeSe : Nodeless Gap with Strong Two-Band Character
• Dome of magnetic order inside the nematic phase of sulfur-substituted FeSe under pressure
• Fermi surface reconstruction in FeSe under high pressure
• Emergence of large quantum oscillation frequencies in thin flakes of the kagome superconductor CsV${}_3$Sb${}_5$
• Quantum phase transitions in two-dimensional superconductors: a review on recent experimental progress
• Collapse of critical nematic fluctuations in FeSe under pressure
• Detection of hole pockets in the candidate type-II Weyl semimetal MoTe${}_2$ from Shubnikov-de Haas quantum oscillations
• Angular dependence of the upper critical field in the high-pressure $1T^{\prime }$ phase of MoTe${}_2$
• Large Fermi surface in pristine kagome metal CsV${}_3$Sb${}_5$ and enhanced quasiparticle effective masses
• Quantum Phase Transition as a Promising Route to Enhance the Critical Current in Kagome Superconductor CsV${}_3$Sb${}_5$
• Discovery of a new phase in thin flakes of KV${}_3$Sb${}_5$ under pressure