Hybrid Quantum Computation

Abstract

This thesis is a study of two main projects. (1) The hybrid quantum computation model that combines the advantages of the unitary-evolution-based quantum computation model and the measurement-based quantum computation model. In the hybrid model, part of a quantum circuit is simulated by unitary evolution and the rest by measurements on star graph states, and the classical information processing requires only an information flow vector and propagation matrices.

(2) The test-state approach---a combination of classical and Grover's algorithm (GA) to the quantum search problem---to find out which one of a permissible set of unitary mappings is implemented by a given black box. GA solves this problem with quadratic speedup as compared with its classical counterpart. A probabilistic outcome of GA is verified with the aid of the test states. The test-state approach, in itself, can complete the search deterministically and 3.41 times as fast as the purely classical search.