Understanding the Protected Nodes and Collapse of the Fermi Arcs in Underdoped Cuprate Superconductors

TL;DR

This paper explains the behavior of Fermi arcs in underdoped cuprate superconductors, linking experimental observations with a phenomenological and microscopic theory to understand the transition to superconducting coherence.

Contribution

It provides a unified phenomenological description of Fermi arc collapse and demonstrates consistency with a microscopic theory, advancing understanding of the superfluid phase in cuprates.

Findings

Fermi arcs collapse into nodes below Tc

Phenomenology aligns with microscopic theory

Good semi-quantitative agreement with experiments

Abstract

We show how recent angle resolved photoemission measurements addressing the Fermi arcs in the cuprates reveal a very natural phenomenological description of the complex superfluid phase. Importantly, this phenomenology is consistent with a previously presented microscopic theory. By distinguishing the order parameter and the excitation gap, we are able to demonstrate how the collapse of the arcs below $T_c$ into well defined nodes is associated with the \emph{smooth} emergence of superconducting coherence. Comparison of this theory with experiment shows good semi-quantitative agreement.