The ability to manipulate the coupling between quantum states in a controllable way has become a major goal in the research of semiconductor-based quantum computation devices. We explore theoretically the use of orbital degrees of freedom to control quantum tunneling in a coupled quantum ring system of two vertically stacked rings with different radii. An external magnetic field can tune excitonic states to have distinct angular momentum ground states, thus blocking recombination processes. Controlled couplings between Stark-shifted direct and indirect exciton states appear as anticrossings in the optical absorption spectrum, allowing the control of the optical activity of the system and possible exciton entanglement.
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