Close Passes Give Atoms Tiny Quantum Kicks

Momentum Kicks Due to Quantum Localization

The momentum changes caused by position measurements are a central feature of wave-particle duality. Here we investigate two cases-localization by a single slit, and which-way detection in the double-slit interference experiment-and examine in detail the associated momentum changes. Particular attention is given to the transfer of momentum between particle and detector, and the recoil of the me...

Random Unitaries Give Quantum Expanders

Quantum tweezer for atoms.

We propose a quantum tweezer for extracting a desired number of neutral atoms from a reservoir. A trapped Bose-Einstein condensate is used as the reservoir, taking advantage of its coherent nature, which can guarantee a constant outcome. The tweezer is an attractive quantum dot, which may be generated by red-detuned laser light. By moving at certain speeds, the dot can extract a desired number ...

Quantum teleportation with atoms: quantum process tomography

The performance of a quantum teleportation algorithm implemented on an ion trap quantum computer is investigated. First the algorithm is analyzed in terms of the teleportation fidelity of six input states evenly distributed over the Bloch sphere. Furthermore, a quantum process tomography of the teleportation algorithm is carried out which provides almost complete knowledge about the algorithm.

Quantum computing and quantum communication with atoms

We review recent theoretical proposals for implementation of quantum computing and quantum communication with atoms. The first example deals with the realization of a universal quantum simulator with atoms and ions. The second example outlines the implementation of a quantum repeater with atomic ensembles.