Practical new platform for interaction-enabled topological phases

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.

5 pages with 3 figures; v2 to appear in PRB/RC. Added 2 page supplement to address robustness against disorder and other technical issues

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Cited by in corpus (6)

• Classification of topological quantum matter with symmetries
• Approximating the Sachdev-Ye-Kitaev model with Majorana wires
• Disorder and interaction in chiral chains: Majoranas vs complex fermions
• Luttinger liquid in contact with a Kramers pair of Majorana bound states
• Majorana stripe order on the surface of a three-dimensional topological insulator
• Engineering of many-body Majorana states in a topological insulator/s-wave superconductor heterostructure