A momentum-dependent perspective on quasiparticle interference in Bi_{2}Sr_{2}CaCu_{2}O_{8+\delta}

TL;DR

This paper reconciles ARPES and STS observations in Bi-2212 by showing that quasiparticle interference patterns can vanish without the actual loss of quasiparticles, highlighting the different natures of the two measurement techniques.

Contribution

It introduces a model explaining the apparent extinction of QPI peaks without quasiparticle loss, resolving a contradiction between ARPES and STS findings in cuprate superconductors.

Findings

ARPES detects quasiparticles across the entire Fermi surface.

QPI peaks can disappear without quasiparticle extinction.

The model explains the different sensitivities of ARPES and STS.

Abstract

Angle Resolved Photoemission Spectroscopy (ARPES) probes the momentum-space electronic structure of materials, and provides invaluable information about the high-temperature superconducting cuprates. Likewise, the cuprate real-space, inhomogeneous electronic structure is elucidated by Scanning Tunneling Spectroscopy (STS). Recently, STS has exploited quasiparticle interference (QPI) - wave-like electrons scattering off impurities to produce periodic interference patterns - to infer properties of the QP in momentum-space. Surprisingly, some interference peaks in Bi_{2}Sr_{2}CaCu_{2}O_{8+\delta} (Bi-2212) are absent beyond the antiferromagnetic (AF) zone boundary, implying the dominance of particular scattering process. Here, we show that ARPES sees no evidence of quasiparticle (QP) extinction: QP-like peaks are measured everywhere on the Fermi surface, evolving smoothly across the AF zone boundary. This apparent contradiction stems from different natures of single-particle (ARPES) and two-particle (STS) processes underlying these probes. Using a simple model, we demonstrate extinction of QPI without implying the loss of QP beyond the AF zone boundary.