An optically driven quantum dot quantum computer

摘要

We propose a design for a quantum computer that builds on n-typenSET structures reported by Tarucha et al. (1996). Our design consists ofnan array of free standing pillars with source and drain electrodes atnthe top and bottom of the pillar and a stacked series of asymmetricnGaAs/AlGaAs quantum wells arrayed along the axis. By applying a negativenbias to the cylindrical gate electrode, carriers near the surface arendepleted. The parabolic electrostatic potential provides confinement innthe radial direction while bandgap discontinuities in the quantum wellsnprovide confinement along the pillar axis. In operating as a quantumncomputer the source and drain are grounded and the number of electronsnin each dot are set to one by adjusting the gate voltage. Qubits arenencoded in the ground state and first excited state of the quantum dotnelectrons. The pillar array constitutes an ensemble of quantum computersnthat operate simultaneously