Anti-Crossing Levels and Electron Tunneling in Quantum Rings

I. Filikhin, S.G. Matinyan, J. Nimmo, B. Vlahovic
North Carolina Central University, US

Keywords: quantum device, effects and spintronics


Quantum Rings (QR) attracted attention during the last decade because of remarkable meso and nano-structures, due to non-simple connected topology. In our work [3] it was shown that in the weakly coupled double concentric quantum rings (DCQRs), placed in transverse magnetic field, the single electron can have spatial transition tunneling between the rings, due to electron level anti-crossing. There is a violation of symmetry of the DCQR by magnetic field, which makes such kind of the tunneling possible. In the present paper, we visualize this features occurring in DCQR composed of GaAs in Al0.70Ga0.30As substrate, and the electron transition between rings under influence of the transverse magnetic field B. We use the single sub-band effective mass approach with energy dependence. We also study correlation between electron localizations and quasi-doublet splitting for complete spectrum in two dimensional InAs/GaAs QR. The bands with different “radial” quantum numbers are well determined by our calculations. The inter-band tunneling is considered in relation to the chaotic properties of the QR. We propose an alternative interpretation of the experimental data to that presented in C. Dembowski et al., where “first experimental evidence for chaos-assisted tunneling” in a microwave billiard was reported.