Transfer of entanglement from electrons to photons by optical selection rules

Abstract

The entanglement transfer from electrons localized in a pair of quantum dots to circularly polarized photons is governed by optical selection rules, enforced by conservation of angular momentum. We point out that the transfer can not be achieved by means of unitary evolution unless the angular momentum of the two initial qubit states differs by 2 units. In particular, for spin-entangled electrons the difference in angular momentum is 1 unit -- so the transfer fails. Nevertheless, the transfer can be successfully completed if the unitary evolution is followed by a measurement of the angular momentum of each quantum dot and post-processing of the photons using the measured values as input.

arXiv comment6 pages; contribution for the focus issue of New Journal of Physics on "Solid State Quantum Information"; revised in response to referee reports

References in corpus (6)

• Entanglement of Formation of an Arbitrary State of Two Qubits
• Discrete entanglement distribution with squeezed light
• Complete conditions for entanglement transfer
• A spin-coherent semiconductor photo-detector for quantum communication
• Entanglement between two superconducting qubits via interaction with non-classical radiation
• Dynamical entanglement-transfer for quantum information networks

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• Entanglement transfer from electrons to photons in quantum dots: An open quantum system approach
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