Chirality-selective proximity effect between chiral $p$-wave superconductors and quantum Hall insulators

TL;DR

This paper investigates the conditions under which a proximity effect occurs between chiral p-wave superconductors and quantum Hall insulators, revealing that chirality alignment induces a topological phase transition to a topological superconductor.

Contribution

It identifies the role of vortex lattices in enabling the proximity effect in quantum Hall states and demonstrates chirality-dependent topological phase transitions in heterostructures.

Findings

Proximity effect depends on vortex lattice presence.

Chirality alignment leads to topological phase transition.

Proximity effect occurs in the lowest Landau level.

Abstract

Heterostructures of superconductors and quantum-Hall insulators are promising platforms of topological quantum computation. However, these two systems are incompatible in some aspects such as a strong magnetic field, the Meissner effect, and chirality. In this work, we address the condition that the superconducting proximity effect works in the bulk of quantum Hall states, and identify an essential role played by the vortex lattice regardless of pairing symmetry. We extend this finding to a heterostructure of a chiral $p$-wave superconductor in the mixed state and an integer quantum Hall insulator. The proximity effect works selectively in the lowest Landau level depending on relative chiralities. If the chiralities align, a topological phase transition to a topological superconductor occurs.