We show that multi-mode entanglement of electrons in a mesoscopic conductor can be detected by a measurement of the zero-frequency current correlations in an electronic Hong-Ou-Mandel interferometer. By this mean, one can further establish a lower bound to the entanglement of formation of two-electron input states. Our results extend the work of Burkard and Loss [Phys. Rev. Lett. 91, 087903 (2003)] to many channels and provide a way to test the existence of entangled states involving both orbital and spin degrees of freedom.
@article{arxiv.cond-mat/0606413,
title = {Electronic Hong-Ou-Mandel interferometer for multi-mode entanglement detection},
author = {Vittorio Giovannetti and Diego Frustaglia and Fabio Taddei and Rosario Fazio},
journal= {arXiv preprint arXiv:cond-mat/0606413},
year = {2008}
}