We propose a compact and highly-efficient scheme for complete Bell-state analysis using two-photon absorption in a superconducting proximity region of a semiconductor avalanche photodiode. One-photon transitions to the superconducting Cooper-pair based condensate in the conduction band are forbidden, whereas two-photon transitions are allowed and are strongly enhanced by superconductivity. This Cooper-pair based two-photon absorption results in a strong detection preference of a specified entangled state. Our analysis shows high detection purity of the desired Bell state with negligible false detection probability. The theoretically-demonstrated concept can pave the way towards practical realizations of advanced quantum information schemes.
@article{arxiv.1702.03944,
title = {Photon Bell-State Analysis Based on Semiconductor-Superconductor Structures},
author = {Evyatar Sabag and Shlomi Bouscher and Raja Marjieh and Alex Hayat},
journal= {arXiv preprint arXiv:1702.03944},
year = {2017}
}