Two qubit conditional quantum logic operation in a single self-assembled quantum dot

TL;DR

This paper demonstrates a two-qubit quantum logic operation using a single semiconductor quantum dot, where optical control enables conditional rotations based on exciton spin states, advancing quantum computing hardware.

Contribution

The work introduces an experimental realization of a conditional quantum gate in a single quantum dot, utilizing exciton-biexciton Rabi rotations for two-qubit operations.

Findings

Successful demonstration of exciton-biexciton Rabi rotation

Implementation of optically gated two-qubit controlled-rotation

Control of target qubit via laser polarization

Abstract

The four-level exciton/biexciton system of a single semiconductor quantum dot acts as a two qubit register. We experimentally demonstrate an exciton-biexciton Rabi rotation conditional on the initial exciton spin in a single InGaAs/GaAs dot. This forms the basis of an optically gated two-qubit controlled-rotation (CROT) quantum logic operation where an arbitrary exciton spin is selected as the target qubit using the polarization of the control laser.