Energy spectrum and persistent current in a nanoscopic elliptical quantum ring threaded by magnetic flux in the presence of Rashba spin–orbit interaction

Abstract

Energy spectrum and persistent current are investigated in an elliptical quantum ring enclosed by a magnetic flux in the presence of Rashba spin–orbit interaction (RSOI) through a tight-binding model. The elliptical quantum ring is composed of M chain rings with N sites in each chain ring. The presence of both elliptical geometry and RSOI leads to the appearance of the energy levels less dependent on magnetic flux in lowest levels in each channel and the splitting of the spin degeneracy. The periodicity of the persistent current oscillations versus magnetic flux is Φ0/(21−ζ2) (Φ0 is the magnetic flux quantum and ζ is the eccentricity) for an elliptical ring with odd N in the half-filled energy levels against Φ0/1−ζ2 for the case of even N. The behavior of the persistent current versus eccentricity depends on N, M, the energy levels filling, and RSOI strength. Moreover, by raising the RSOI strength, the amplitude of the persistent current oscillates independent of eccentricity. Therefore, an elliptical quantum ring with the tunable electric field can be applicable as switching devices in nanoelectronics.