Research: Fractional angular momentum at topological insulator interfaces

An s-wave superconductor proximate to a topological insulator features vortices with Majorana zero modes bound states at their cores. In this work we have shown that such Majorana-vortex composites at the interface carry also a fractional electric charge and a fractional angular momentum. We propose an experiment to measure the fractional angular momentum based on a Josephson junction array with a flux island on the surface of a topological insulator as illustrated in the figure. The resulting interference pattern would show a signal corresponding to a quasi-particle having fractional angular momentum.  The underlying quasi-particle is an anyon.

F. S. Nogueira, Z. Nussinov, J. van den Brink,
Fractional angular momentum at topological insulator interfaces,
Physical Review Letters 121, 227001 (2018) (arXiv)