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 (4, 6) with the quantum dot formed by a further gate electrode (8). The invention also comprises means for generating a electrostatic wave propagating along the wire, such as a surface acoustic wave transducer (10). 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.

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 (4, 6) with the quantum dot formed by a further gate electrode (8). The invention also comprises means for generating a electrostatic wave propagating along the wire, such as a surface acoustic wave transducer (10). 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.

Abstract: A lateral junction semiconductor device and method for fabricating the same comprising the steps of taking a semiconductor structure having a stack formed by a plurality of layers of semiconductor material arranged in a series of substantially parallel planes, the semiconductor material within a first layer having an excess of charge carriers of a first polarity at a first concentration, and selectively removing semiconductor material from the first layer to a depth which varies along a first direction substantially parallel with the planes of the layers within the structure, so as to provide a gradation of the concentration of charge carriers of first polarity within an active layer along the first direction. A photon source comprising said lateral junction semiconductor device.

Abstract: A lateral junction semiconductor device and method for fabricating the same comprising the steps of taking a semiconductor structure having a stack formed by a plurality of layers of semiconductor material arranged in a series of substantially parallel planes, the semiconductor material within a first layer having an excess of charge carriers of a first polarity at a first concentration, and selectively removing semiconductor material from the first layer to a depth which varies along a first direction substantially parallel with the planes of the layers within the structure, so as to provide a gradation of the concentration of charge carriers of first polarity within an active layer along the first direction. A photon source comprising said lateral junction semiconductor device.