Zero-voltage conductance peak from weak antilocalization in a Majorana nanowire

TL;DR

This paper demonstrates that weak antilocalization effects in disordered superconducting nanowires can produce zero-voltage conductance peaks similar to Majorana zero modes, complicating their identification.

Contribution

It reveals that weak antilocalization can mimic Majorana signatures in conductance measurements without requiring a topologically nontrivial phase.

Findings

Weak antilocalization can produce zero-bias peaks of order e^2/h.

Particle-hole symmetry enables quantum interference despite disorder.

Methods are proposed to distinguish Majorana resonances from weak antilocalization effects.

Abstract

We show that weak antilocalization by disorder competes with resonant Andreev reflection from a Majorana zero-mode to produce a zero-voltage conductance peak of order e^2/h in a superconducting nanowire. The phase conjugation needed for quantum interference to survive a disorder average is provided by particle-hole symmetry - in the absence of time-reversal symmetry and without requiring a topologically nontrivial phase. We identify methods to distinguish the Majorana resonance from the weak antilocalization effect.