Practical new platform for interaction-enabled topological phases

TL;DR

This paper proposes a new platform using vortex lattices in topological insulators to realize interaction-enabled topological phases with Majorana fermions, expanding experimental possibilities for exotic quantum states.

Contribution

It introduces a practical platform for observing interaction-enabled topological phases in fermionic systems with time reversal symmetry, utilizing Majorana fermions in vortex lattices.

Findings

Proposes vortex lattices in topological insulators as a new experimental platform.

Demonstrates how interactions and symmetry lead to novel topological phases.

Discusses methods for tuning and detecting these phases experimentally.

Abstract

Systems of strongly interacting particles, fermions or bosons, can give rise to topological phases that are not acessible to non-interacting systems. Many such interaction-enabled topological phases have been discussed theoretically but few experimental realizations exists. Here we propose a new platform for interacting topological phases of fermions with time reversal symmetry $\bar T$ (such that $\bar T^2=1$) that can be realized in vortex lattices in the surface state of a topological insulator. The constituent particles are Majorana fermions bound to vortices and antivortices of such a lattice. We explain how the $\bar T$ symmetry arises and discuss ways in which interactions can be experimentally tuned and detected. We show how these features can be exploited to realize a class of interaction-enabled crystalline topological phases that have no analog in weakly interacting systems.