Epr pair generation

Abstract

The present invention relates to the formation of electron spin EPR pairs and manipulation of such entangled electrons. The invention comprises a static quantum dot located part way along a quantum wire with means for adjusting the confining potential of the quantum dot. The quantum wire may for instance be formed by gate electrode () with the quantum dot formed by a further gate electrode (). The invention also comprises means for generating a electrostatic wave propagating along the wire, such as a surface acoustic wave transducer (). In use a pair of electrons may be loaded into the static quantum dot and allowed to relax to a singlet ground state, in which the electrons are spin entangled. The propagating electrostatic wave acts as a series of quantum dots moving along the quantum wire. The confining potential of the static quantum dot is adjusted in time with arrival of a moving quantum dot so that one of the spin entangled electrons will tunnel to the moving quantum dot with preserved entanglement. The same process can be used to separately eject the remaining electron. The process can also be applied in reverse transport electrons from a moving quantum dot into a static dot.