Properties of an α-T3 Aharonov-Bohm quantum ring: Interplay of Rashba spin-orbit coupling and topological defect

Abstract: In this paper we investigate the interplay of the Rashba spin-orbit coupling (RSOC) and a topological defect, such as a screw dislocation in an {\alpha}-T3 Aharonov-Bohm quantum ring and scrutinized the effect of an external transverse magnetic field therein. Our study reveals that the energy spectrum follows a parabolic dependence on the Burgers vector associated with the screw dislocation. Moreover, its presence results in an effective flux, encompassing the ramifications due to both the topological flux and that due to the external magnetic field. Furthermore, we observe periodic oscillations in the persistent current in both charge and spin sectors, with a period equal to one flux quantum, which, however suffers a phase shift that is proportional to the dislocation present in the system. Such tunable oscillations of the spin persistent current highlights potential application of our system to be used as spintronic devices. Additionally, we derive and analyse the thermodynamic properties of the ring via obtaining the canonical partition function through Euler-Maclaurin formula. In particular, we compute the thermodynamic potentials, free energies, entropy, and heat capacity and found the latter to yield the expected Dulong-Petit law at large temperatures.