Quasiparticle Interference in STM As a Function of Temperature: Signatures of Coherence

TL;DR

This study investigates how quasiparticle interference patterns in STM change with temperature, revealing two energy gap scales and emphasizing the importance of quasiparticle coherence in cuprates.

Contribution

It demonstrates the temperature dependence of QPI patterns and predicts energy gap behaviors, linking quasiparticle coherence to experimental signatures in underdoped cuprates.

Findings

QPI pattern is highly sensitive to quasiparticle coherence.

Two distinct energy gap scales are observed in the QPI data.

Predictions for temperature-dependent energy gaps in underdoped cuprates.

Abstract

In this paper we explore the behavior of the quasi-particle interference pattern (QPI) of scanning tunneling microscopy as a function of temperature, $T$. After insuring a minimal consistency with photoemission, we find that the QPI pattern is profoundly sensitive to quasi-particle coherence and that it manifests two energy gap scales. The nearly dispersionless QPI pattern above $T_c$ is consistent with data on moderately underdoped cuprates. To illustrate the important two energy scale physics we present predictions of the QPI--inferred energy gaps as a function of $T$ for future experiments on moderately underdoped cuprates.