Quasiparticle spectroscopy and high-field phase diagrams of cuprate superconductors -- An investigation of competing orders and quantum criticality

TL;DR

This study uses spectroscopic and thermodynamic methods to explore the phase diagrams of cuprate superconductors, revealing evidence of a quantum critical point near a phase with coexisting superconductivity and spin-density wave order.

Contribution

It provides experimental evidence supporting the existence of a quantum critical point and competing orders in cuprates, advancing understanding of their complex phase diagram.

Findings

Proximity of cuprates to a quantum critical point separating pure SC and coexisting phases.

Identification of spin-density wave as a likely competing order.

Influence of magnetic field, tunneling current, and disorder on competing orders.

Abstract

We present scanning tunneling spectroscopic and high-field thermodynamic studies of hole- and electron-doped (p- and n-type) cuprate superconductors. Our experimental results are consistent with the notion that the ground state of cuprates is in proximity to a quantum critical point (QCP) that separates a pure superconducting (SC) phase from a phase comprised of coexisting SC and a competing order, and the competing order is likely a spin-density wave (SDW). The effect of applied magnetic field, tunneling current, and disorder on the revelation of competing orders and on the low-energy excitations of the cuprates is discussed.