Crystalline Symmetry-Protected Majorana Mode in Number-Conserving Dirac Semimetal Nanowires

TL;DR

This paper demonstrates that a Dirac semimetal nanowire, protected by crystalline symmetry and driven by magnetic flux, can host Majorana zero modes without requiring superconductivity, advancing topological quantum computation platforms.

Contribution

It introduces a novel number-conserving platform using Dirac semimetal nanowires to realize symmetry-protected Majorana modes, avoiding issues from interchannel tunneling.

Findings

Majorana zero modes can emerge in Dirac semimetal nanowires with magnetic flux.

Crystalline symmetry protects the topological degeneracy of Majorana modes.

Experimental signatures of Majorana signals are discussed.

Abstract

One of the cornerstones for topological quantum computations is the Majorana zero mode, which has been intensively searched in fractional quantum Hall systems and topological superconductors. Several recent works suggest that such an exotic mode can also exist in a one-dimensional (1D) interacting double-wire setup even without long-range superconductivity. A notable instability in these proposals comes from interchannel single-particle tunneling that spoils the topological ground state degeneracy. Here we show that a 1D Dirac semimetal (DSM) nanowire is an ideal number-conserving platform to realize such Majorana physics. By inserting magnetic flux, a DSM nanowire is driven into a 1D crystalline-symmetry-protected semimetallic phase. Interaction enables the emergence of boundary Majorana zero modes, which is robust as a result of crystalline symmetry protection. We also explore several experimental consequences of Majorana signals.