Manipulation of Majorana bound states in proximity to a quantum ring with Rashba coupling

Abstract

The quest for Majorana zero modes in the laboratory is an active field of research in condensed matter physics. In this regard, there have been many theoretical proposals; however, their experimental detection remains elusive. In this article, we present a realistic setting by considering a quantum ring with Rashba spin-orbit coupling and threaded by a magnetic flux, in contact with a topological superconducting nanowire. We focus on spin-polarized persistent currents to assess the existence of Majorana zero modes. We find that the Rashba spin-orbit coupling allows for tuning the position of the zero energy crossings in the flux parameter space and has sizable effects on spin-polarized persistent currents. We believe that our results will contribute towards probing the existence of Majorana zero modes.

Anomalous Spin Textures in a 2D Topological Superconductor Induced by Point Impurities

“…The ST can be obtained following Equation (12b). Thus, for this impurity s(r, z) = 𝛾 sin 𝜃 e z (15) From Figure 3 we can see that the component along the z direction is asymmetric in the y direction, presenting clear signatures of Friedel oscillations. This could be the reason of the observed variation of the period of the ST as the energy increases.…”

“…[4,5,9] Both types of superconductors are rare in nature and, therefore, proposals have focused on the use of topological insulators (TIs) on which a layer of a conventional superconductor is deposited to induce superconductivity by the proximity effect. [10] In turn, a number of theoretical proposals [11][12][13][14][15] have been put forward to demonstrate the existence of these quasi-particles. However, its presence in these material systems has not yet been unequivocally determined and this area of condensed matter physics is far from being fully understood.…”