All-electrical coherent control of the exciton states in a single quantum dot

TL;DR

This paper demonstrates high-fidelity electrical control of exciton spin states in a quantum dot, enabling coherent transfer and manipulation of quantum information between photons and electron-hole pairs for solid-state quantum computing.

Contribution

It introduces a method for all-electrical coherent control of exciton states in a quantum dot, achieving near-unity fidelity in quantum gate operations.

Findings

Reversible transfer of quantum information from photon polarization to exciton spin states.

Electrical manipulation of spins on sub-nanosecond timescales.

Implementation of phase-shift and spin-flip gates with high fidelity.

Abstract

We demonstrate high-fidelity reversible transfer of quantum information from the polarisation of photons into the spin-state of an electron-hole pair in a semiconductor quantum dot. Moreover, spins are electrically manipulated on a sub-nanosecond timescale, allowing us to coherently control their evolution. By varying the area of the electrical pulse, we demonstrate phase-shift and spin-flip gate operations with near-unity fidelities. Our system constitutes a controllable quantum interface between flying and stationary qubits, an enabling technology for quantum logic in the solid-state.