Tailoring Quantum Oscillations of Excitonic Schrodinger Cats as Qubits

Quantum oscillations of photocapacitance measured over a large area indicate many-body cooperative phenomena of dipolar excitons. Presence and absence of splitting of excitonic photocapacitance spectra at periodic bias intervals point towards tunneling induced quantum coupling. Negative quantum capacitance and interference beats of photocapacitance oscillation both establish the presence of long range spatial correlation among these indirect excitons in the transverse XY plane. We demonstrated that the characteristic narrowing in momentum space of Bose-Einstein condensate of long-lived, indirect excitons is directly related to the presence of coherent resonant tunneling in a double-barrier heterostructure having zero-dimensional quantum dots beside a two-dimensional quantum well. All these observations can also be explained as collective Rabi oscillations of macroscopically large, multipartite, two-level, coupled and uncoupled quantum states of excitonic condensate as qubits. Hence, we argue that photocapacitance is unique in its ability to probe the macroscopic phase coherence of very large number of excitonic qubits as a function of both light intensity and applied bias, which can be scaled up for viable quantum computation having superior functionalities.