Posted On: 11/16/2014 8:56:28 PM
Post# of 22463
A promising technology for quantum information processing?
5th November 2014
Researchers produce entangled photon pairs from quantum dots in nanowires
For implementing ambitious quantum information processing schemes, such as quantum repeaters, you need a bright photon source that combines high-fidelity entanglement, on-demand generation, high extraction efficiency, directional and coherent emission, as well as position control at the nanoscale. So far all of these properties have yet to be achieved in a single device.
Semiconductor quantum dots embedded in nanowire waveguides look like a promising candidate. This is because the high refractive index of a nanowire waveguide around a quantum dot ensures that the emitted light is guided in the desired direction and a tapered end makes the light extraction very efficient. However, entanglement has not yet been demonstrated for a nanowire quantum dot - until now.
Scientists from Delft University of Technology, the National Research Council of Canada, Politecnico di Milano, and Micro Photon Devices have shown a bright and coherent source of strongly entangled photon pairs from a position-controlled nanowire quantum dot with a fidelity as high as 0.859±0.006 and concurrence of 0.80±0.02. The InP nanowires contained single InAsP quantum dots and were grown using chemical beam epitaxy.
The report published in Nature Communications, also shows how the two-photon quantum state is modified via the nanowire shape.
The researchers say that the new nanoscale entangled photon source can be integrated at desired positions in a quantum photonic circuit, single-electron devices and light-emitting diodes.
http://www.compoundsemiconductor.net/article/...ssing.html
5th November 2014
Researchers produce entangled photon pairs from quantum dots in nanowires
For implementing ambitious quantum information processing schemes, such as quantum repeaters, you need a bright photon source that combines high-fidelity entanglement, on-demand generation, high extraction efficiency, directional and coherent emission, as well as position control at the nanoscale. So far all of these properties have yet to be achieved in a single device.
Semiconductor quantum dots embedded in nanowire waveguides look like a promising candidate. This is because the high refractive index of a nanowire waveguide around a quantum dot ensures that the emitted light is guided in the desired direction and a tapered end makes the light extraction very efficient. However, entanglement has not yet been demonstrated for a nanowire quantum dot - until now.
Scientists from Delft University of Technology, the National Research Council of Canada, Politecnico di Milano, and Micro Photon Devices have shown a bright and coherent source of strongly entangled photon pairs from a position-controlled nanowire quantum dot with a fidelity as high as 0.859±0.006 and concurrence of 0.80±0.02. The InP nanowires contained single InAsP quantum dots and were grown using chemical beam epitaxy.
The report published in Nature Communications, also shows how the two-photon quantum state is modified via the nanowire shape.
The researchers say that the new nanoscale entangled photon source can be integrated at desired positions in a quantum photonic circuit, single-electron devices and light-emitting diodes.
http://www.compoundsemiconductor.net/article/...ssing.html
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