Localization of electronic states resulting from electronic topological transitions in the Mo1−xRex alloys: A photoemission study

Abstract

We present the results of resonant photoemission spectroscopy experiments on Mo1−xRex alloy compositions spanning over two electronic topological transitions (ETTs) at critical concentrations xC1=0.05 and xC2=0.11. Photoelectrons show an additional resonance (R3) in constant initial state spectra of alloys along with two resonances (R1 and R2), which are similar to those observed in molybdenum. All the resonances show Fano-like line shapes. Asymmetry parameter q of resonances R1 and R3 of alloys is observed to be large and negative. Our analysis suggests that the origin of large negative q is associated with phonon assisted interband scattering between Mo-like states and the narrow band that appeared due to ETT.

Proximity Effect between a Two-Band Superconductor and a Ferromagnet

“…From the fundamental point of view, Mo-Re alloys is an excellent example of the statement that in alloys with high concentrations of scattering centres small variations in the density of electronic states can introduce pronounced effects. Indeed, the addition of Re impurities to pure Mo led to a growth in the electron concentration, thereby bringing the Fermi level of the system closer to the critical energies of the electronic spectrum of molybdenum [17]. As a result, a transformation of the electron spectrum takes place, namely, the appearance of a new Fermi-surface cavity of ≅ 10 at.% of a Re concentration and then partial localization of electrons belonging to the new d group.…”