Tailoring Quantum Oscillations of Excitonic Schrodinger’s Cats as Qubits*

We report [https://arxiv.org/abs/2107.13518] experimental detection and control of Schrodinger’s Cat like macroscopically large, quantum coherent state of a two-component Bose-Einstein condensate of spatially indirect electron-hole pairs or excitons. Phase coherent periodic oscillations in photo generated capacitance as a function of applied voltage bias and light intensity over a macroscopically large area are measured. Coherent resonant tunneling in this well-dot heterostructure restricts the available momentum space of the charge carriers within this quantum well. Consequently, the average electric polarization vector of the associated indirect excitons collectively orients along the direction of applied bias and these excitons undergo Bose-Einstein condensation below ~100 K. Finally, we observe collective Rabi oscillations of these macroscopically large, ‘multipartite’, two-level, coupled and uncoupled quantum states of excitonic condensate as qubits. Moreover, some of these excitons undergoing BEC can be addressed independently of others using applied bias over a localized region to satisfy, in principle, the DiVincenzo’s criteria for scalable quantum computation.