| Quantum computation is the combination of quantum mechanics and computer science. Compared with classical one, quantum computers manifest distinct advantages in many respects, for example, to cope with some certain problems which are NP problems for classical computers and to simulate the evolution of quantum system, and so on. Significant progresses have recently been achieved in the Field of quantum computing. Nevertheless, There are still many difficulties and challenges in physical implementation of quantum computation. The infidelity of quantum gates is one of them. To suppress the infidelity to an acceptable level, a promising approach based on geometric phases was proposed as well as quantum encoding scheme. The geometric phase depends only on the global feature of the evolution path and is believed to be robust against local fluctuations. It seems helpful to achieve built-in fault-tolerant quantum gates. In this dissertation, we investigate how to construct geometric quantum computation in NMR system, superconductivity charge qubit, and propose an attractive scheme to realize holonomic quantum computation in DFS with trapped ions. The main contents of this thesis include:1. Introduction of the fundamental theory of quantum computation.The idea of quantum computation was first mentioned by Richard. P. Feymann in 1982. Compared with classical one, quantum computer takes its power from superposition and entanglement, which are two main features distinguishing the quantum world from the classical world. But they are also very fragile and may be destroyed easily by a process called decoherence. Quantum error-correcting codes enable quantum computers to operate despite some degree of decoherence and may make quantum computers experimentally realizable, provided that the noise in individual quantum gates is below a certain constant threshold.2. Physical systems used to construct quantum computer.The geometric quantum computation(GQC) and its physical implementation were... |
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