Friday, January 11, 2013

1301.2144 (Asier Pineiro-Orioli et al.)

Noise effects and tomography of remote entangled spins in quantum dots    [PDF]

Asier Pineiro-Orioli, Dara P. S. McCutcheon, Terry Rudolph
We investigate decoherent effects on, and propose a tomographic procedure to measure the entangled state of two quantum dots in micro cavities, established via the exchange and subsequent measurement of a photon. Making the realistic assumption of noise dominated by pure-dephasing processes, we find that the photon must be exchanged and measured on timescales shorter than the quantum dots' characteristic dephasing time for appreciable levels of entanglement to be achieved. The tomographic scheme is able to reconstruct the full density matrix of the quantum dots, and requires only single spin rotations and the injection of an additional photon. Remarkably, we find that the additional photon need not be exchanged and measured on a timescale shorter than the dephasing time for accurate tomography, and also allows many to be used in order to increase the measurement signal.
View original: http://arxiv.org/abs/1301.2144

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