We analyzed the fidelity of the quantum state transfer (QST) from a photon-polarization qubit to an electron-spin-polarization qubit in a semiconductor quantum dot, with special attention to the exchange interaction between the electron and the simultaneously created hole. In order to realize a high-fidelity QST we had to separate the electron and hole as soon as possible, since the electron-hole exchange interaction modifies the orientation of the electron spin. Thus, we propose a double-dot structure to separate the electron and hole quickly, and show that the fidelity of the QST can reach as high as 0.996 if the resonant tunneling condition is satisfied.
@article{arxiv.quant-ph/0608188,
title = {Effect of exchange interaction on fidelity of quantum state transfer from a photon qubit to an electron-spin qubit},
author = {Yoshiaki Rikitake and Hiroshi Imamura},
journal= {arXiv preprint arXiv:quant-ph/0608188},
year = {2009}
}
Comments
5 pages, 4 figures, to be published in Phys. Rev. B Rapid Communications