On the production and transfer of entangled electrons and photons

Mikhail Vladimirovich Fedorov, Maxim A. Efremov, P. A. Volkov

Verónica Cerletti, Oliver Gywat, Daniel Loss

We show that electron recombination using positively charged excitons in single quantum dots provides an efficient method to transfer entanglement from electron spins onto photon polarizations. We propose a scheme for the production of entangled four-photon states of GHZ type. From the GHZ state, two fully entangled photons can be obtained by a measurement of two photons in the linear polarization basis, even for quantum dots with observable fine structure splitting for neutral excitons and significant exciton spin decoherence. Because of the interplay of quantum mechanical selection rules and interference, maximally entangled electron pairs are converted into maximally entangled photon pairs with unity fidelity for a continuous set of observation directions. We describe the dynamics of the conversion process using a master-equation approach and show that the implementation of our scheme is feasible with current experimental techniques.

Amaal M. Ali, Natasha Bastien, Wendy-Ann Gibbons +2 more

Zhen-Sheng Yuan, Xiao‐Hui Bao, Chao‐Yang Lu +3 more

L. J. P. Ament, C. W. J. Beenakker

Building on an earlier proposal for the production of polarization-entangled microwaves by means of intraband transitions in a pair of quantum dots, we show how this device can be used to transfer an unknown single-qubit state from electronic charge to photonic polarization degrees of freedom. No postselection is required, meaning that the quantum state transfer happens deterministically. Decoherence of the charge qubit causes a nonmonotonic decay of the fidelity of the transferred state with an increasing decoherence rate.

Todd S. Larchuk