Optical Control of 2-Qubit Exciton States in a Coupled Quantum Dot

Abstract

We investigated the formation dynamics of an artificial exciton molecule state, which consists of two different excitons confined in each quantum dot of a pair of quantum dots, namely, a coupled quantum dot (CQD). By the selective optical excitation of the inherent energy states of two different excitons using two-color pulsed excitation, we created an artificial exciton molecule state and investigated the transient dynamics, and monitored the photoluminescence, namely, the population of the artificial exciton molecule states. By employing the power dependence of the two colors, we tried the two-qubit logic gate operation and succeeded in controlling the population of an artificial exciton molecule (pulse area θ<π).