Localization of electronic states resulting from electronic topological transitions in the Mo$_{1-x}$Re$_x$ alloys: A photoemission study

TL;DR

This study uses resonant photoemission spectroscopy to investigate electronic state localization in Mo-Re alloys across two electronic topological transitions, revealing phonon-assisted interband scattering effects.

Contribution

It provides new insights into the electronic state localization and scattering mechanisms in Mo-Re alloys during topological transitions using photoemission spectroscopy.

Findings

Identification of an additional resonance R3 in alloys

Large negative asymmetry parameter q linked to phonon-assisted scattering

Observation of Fano-like line shapes in resonances

Abstract

We present the results of resonant photoemission spectroscopy experiments on the Mo$_{1-x}$Re$_{x}$ alloy compositions spanning over two electronic topological transitions (ETT) at the critical concentrations $x_{C1}$ = 0.05 and $x_{C2}$ = 0.11. The photoelectrons show an additional resonance ($R3$) in the constant initial state (CIS) spectra of the alloys along with two resonances ($R1$ and $R2$) which are similar to those observed in molybdenum. All the resonances show Fano-like line shapes. The asymmetry parameter $q$ of the resonances $R1$ and $R3$ of the alloys is observed to be large and negative. Our analysis suggests that the origin of large negative q is associated with phonon assisted inter band scattering between the Mo-like states and the narrow band that appeared due to the ETT.