Majorana Zero Modes in Fermionic Wires coupled by Aharonov-Bohm Cages

TL;DR

This paper proposes a geometry-based, number-conserving method to realize Majorana Zero Modes in interacting fermionic ladders with Aharonov-Bohm cages, supported by analytical and numerical evidence.

Contribution

It introduces a novel, geometry-driven scheme for Majorana modes that preserves particle number and demonstrates an extended topological phase through bosonization and matrix-product-state simulations.

Findings

Extended topological region identified in parameter space

Adiabatic connection to known models established

Potential experimental realizations discussed

Abstract

We devise a number-conserving scheme for the realization of Majorana Zero Modes in an interacting fermionic ladder coupled by Aharonov-Bohm cages. The latter provide an efficient mechanism to cancel single-particle hopping by destructive interference. The crucial parity symmetry in each wire is thus encoded in the geometry of the setup, in particular, its translation invariance. A generic nearest-neighbor interaction generates the desired correlated hopping of pairs. We exhibit the presence of an extended topological region in parameter space, first in a simplified effective model via bosonization techniques, and subsequently in a larger parameter regime with matrix-product-states numerical simulations. We demonstrate the adiabatic connection to previous models, including exactly-solvable ones, and we briefly comment on possible experimental realizations in synthetic quantum platforms, like cold atomic samples.