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.
@article{arxiv.1011.2641,
title = {All-electrical coherent control of the exciton states in a single quantum dot},
author = {A. Boyer de la Giroday and A. J. Bennett and M. A. Pooley and R. M. Stevenson and N. Skold and R. B. Patel and I. Farrer and D. A. Ritchie and A. J. Shields},
journal= {arXiv preprint arXiv:1011.2641},
year = {2012}
}