Unconventional Low-Energy Excitations of Cuprate Superconductors

TL;DR

This paper reviews the unconventional low-energy excitations in cuprate superconductors, emphasizing competing orders and their role in phenomena like pseudogaps, Fermi arcs, and conductance modulations, offering a unified phenomenological understanding.

Contribution

It introduces a phenomenological framework based on competing orders to explain diverse experimental observations in cuprate superconductors.

Findings

Competing orders explain pseudogaps and Fermi arcs.

Unified phenomenology accounts for conductance modulations.

Compatibility with pre-formed pairs and phase fluctuations.

Abstract

Recent development in the physics of high-temperature cuprate superconductivity is reviewed, with special emphasis on the phenomena of unconventional and non-universal low-energy excitations of hole- and electron-type cuprate superconductors and the possible physical origin. A phenomenology based on coexisting competing orders with cuprate superconductivity in the ground state appears to provide consistent account for a wide range of experimental findings, including the presence (absence) of pseudogaps and Fermi arcs above the superconducting transition $T_c$ in hole-type (electron-type) cuprate superconductors and the novel conductance modulations below $T_c$, particularly in the vortex state. Moreover, the competing order scenario is compatible with the possibility of pre-formed Cooper pairs and significant phase fluctuations in cuprate superconductors. The physical implications of the unified phenomenology and remaining open issues for the microscopic mechanism of cuprate superconductivity are discussed.