An important problem in Quantum Information Processing is the so-called “rapid reset” problem, where in qubits must be quickly initialized so that they might be reused in computations. Many researchers have tried to solve this problem by creating platforms where the spontaneous emission rate is increased, but their schemes created another problem – namely one of reducing the coherence essential for quantum computation. By controlling the polarization of light, Chris DiLoreto and Chitra Rangan of the University of Windsor have devised a novel scheme that can both do a rapid reset, and maintain coherence during computations. Their scheme involves a quantum dot coupled to a silver nanoparticle dimer, and changes the spontaneous emission rate of a quantum emitter on demand. This is an important conceptual advance that can be experimentally implemented in any quantum computing platform that has an asymmetric cavity.
For more information see: DiLoreto C, Rangan C. (2017). Polarization control of spontaneous emission for rapid quantum state initialization. Physical Review A. 95, 043834.