Multiband electronic transport in $\alpha$-Yb$_{1-x}$Sr$_{x}$AlB$_{4}$ [x = 0, 0.19(3)] single crystals

TL;DR

This study provides evidence of multiband electronic transport in $ ext{YbAlB}_4$ and its Sr-doped variant, revealing how Sr substitution affects conductivity without altering heavy fermion quasiparticle masses.

Contribution

It demonstrates multiband transport in these compounds and shows Sr doping enhances conductivity without changing quasiparticle masses.

Findings

Multiband transport appears below 10 K in both compounds.

Sr substitution increases conductivity.

Heavy fermion quasiparticle masses remain unchanged with Sr doping.

Abstract

We report on the evidence for the multiband electronic transport in $\alpha$-YbAlB$_{4}$ and $\alpha$-Yb$_{0.81(2)}$Sr$_{0.19(3)}$AlB$_{4}$. Multiband transport reveals itself below 10 K in both compounds via Hall effect measurements, whereas anisotropic magnetic ground state sets in below 3 K in $\alpha$-Yb$_{0.81(2)}$Sr$_{0.19(3)}$AlB$_{4}$. Our results show that Sr$^{2+}$ substitution enhances conductivity, but does not change the quasiparticle mass of bands induced by heavy fermion hybridization.