Volume 533, Issue 12 2100305
Research Article

Josephson and Persistent Currents in a Quantum Ring between Topological Superconductors

Fabián Medina

Corresponding Author

Fabián Medina

Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile

E-mail: [email protected]

Search for more papers by this author
Juan Pablo Ramos-Andrade

Juan Pablo Ramos-Andrade

Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile

Search for more papers by this author
Luis Rosales

Luis Rosales

Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile

Search for more papers by this author
Pedro Orellana

Pedro Orellana

Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile

Search for more papers by this author
First published: 29 October 2021

Abstract

In this work, the spectra in an Aharonov–Bohm quantum-ring interferometer forming a Josephson junction between two topological superconductor (TSC) nanowires are investigated. The TSCs host Majorana bound states at their edges, and both the magnetic flux and the superconducting phase difference between the TSCs are used as control parameters. A tight-binding approach is used to model the quantum ring coupled to both TSCs, described by the Kitaev effective Hamiltonian. The problem is solved by means of exact numerical diagonalization of the Bogoliubov-de Gennes Hamiltonian and obtain the spectra for two sizes of the quantum ring as a function of the magnetic flux and the phase difference between the TSCs. Depending on the size of the quantum ring and the coupling, the spectra display several patterns. Those are denoted as line, point, and undulated nodes, together with flat bands, which are topologically protected. The first three patterns can be possibly detected by means of persistent and Josephson currents. Hence, the results could be useful to understand the spectra and their relation with the behavior of the current signals.

Conflict of Interest

The authors declare no conflict of interest.

Data Availability Statement

Research data are not shared.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.