Andreev spectroscopy of doped HgTe quantum wells

TL;DR

This paper explores Andreev reflection in doped HgTe quantum wells, revealing how it probes Dirac fermion dynamics and can exhibit both specular and retroreflection despite Fermi wavelength mismatches.

Contribution

It demonstrates that Andreev conductance can effectively probe massive Dirac fermion dynamics in HgTe quantum wells, including the realization of both reflection types under Fermi mismatch conditions.

Findings

Andreev conductance probes Dirac fermion dynamics

Both specular and retroreflection observed

Reflection types persist despite Fermi wavelength mismatch

Abstract

We investigate the Andreev reflection process in high-mobility HgTe/CdTe quantum wells. We find that Andreev conductance probes the dynamics of massive 2+1 Dirac fermions, and that both specular Andreev reflection and retroreflection can be realized even in presence of a large mismatch between the Fermi wavelengths at the two sides of the normal/superconducting junction.