Lower bound for electron spin entanglement from beamsplitter current correlations
Abstract
We determine a lower bound for the entanglement of pairs of electron spins injected into a mesoscopic conductor. The bound can be expressed in terms of experimentally accessible quantities, the zero-frequency current correlators (shot noise power or cross-correlators) after transmission through an electronic beam splitter. The effect of spin relaxation (T_1 processes) and decoherence (T_2 processes) during the ballistic coherent transmission of the carriers in the wires is taken into account within Bloch theory. The presence of a variable inhomogeneous magnetic field allows the determination of a useful lower bound for the entanglement of arbitrary entangled states. The decrease in entanglement due to thermally mixed states is studied. Both the entanglement of the output of a source (entangler) and the relaxation (T_1) and decoherence (T_2) times can be determined.
Cite
@article{arxiv.cond-mat/0303209,
title = {Lower bound for electron spin entanglement from beamsplitter current correlations},
author = {Guido Burkard and Daniel Loss},
journal= {arXiv preprint arXiv:cond-mat/0303209},
year = {2007}
}
Comments
4 pages, 3 figures