One-way quantum computing in optical lattices with many atom addressing.

摘要

Ultracold atones in optical lattices are a promising test bed for quantum computation and simulation. The relative ease with which large cluster states, a special class of entangled state, can be generated in optical lattices makes them particularly attractive for the implementation of one-way quantum computing (1WQC). Given the cluster state as a resource, 1WQC requires only the ability to make sequential measurements ore isolated qubits. Unfortunately, this requirement poses a major challenge for 1WQC in optical lattice systems because the spacing between atomic qubits is generally smaller than the width of addressing beams. This thesis will examine the problems associated with many atom addressing in the context of 1WQC and show that even without the ability to address single atoms 1WQC is still possible. It is shown how, with many qubit rotations, one can arbitrary choose the rotation applied to N qubits using N accurately positioned rotation bearers. This thesis also presents a simple method to increase the probability of measuring only a single cluster qubit, at the cost of additional operational overhead. Finally a measurement protocol is presented which, by increasing the overall cluster size, compensates for errors which arise when an arbitrary number of nearby cluster qubits are accidentally measured.