We investigate the chiral quantum walk (CQW) for entanglement transfer on a triangular chain. We specifically consider two and three site Bell and W type entanglement cases, respectively. Using concurrence as quantum entanglement measure, together with the Bures distance and trace distance as the measures of the fidelity of the state transfer, we evaluate the success of the entanglement transfer. We compare the entangled state transfer time and quality in CQW against continuous-time quantum random walk. Furthermore, how the chain length and back-scattering at the end of the chain influence the entanglement transfer are pointed out.

We propose to integrate dark-state based localization techniques into a neutral atom quantum computing architecture and numerically investigate two specific schemes. The first scheme implements state-selective projective measurement by scattering photons from a specific qubit with very little cross talk on the other atoms in the ensemble. The second scheme performs a single-qubit phase gate on the target atom with an incoherent spontaneous emission probability as low as 0.01. Our numerical simulations in rubidium (Rb) atoms show that for both of these schemes a spatial resolution at the level of tens of nanometers using near-infrared light can be achieved with experimentally realistic parameters.

No abstract