Solid-state Quantum Information Processing And Trapped-ion Quantum Simulation

The science of quantum computation and quantum information is the utilization of quantum mechanics to represent and manipulate information, which has capabilities that exceed those of traditional classical information techniques and shown tremendous potential applications. Thus, this matter of fact has triggered lots of research. Among the present various physical systems suitable for quantum computation and quantum information, The solid-state system, such as endohedral fullerenes, is considered as one of the candidates for quantum information processing due to the long coherence time. Nevertheless, limited by current experimental conditions, although quantum computation has made great progress both theoretically and experimentally, the realization of a universal quantum computer still poses formidable experimental challenges. Therefore, researchers hope to build a device not quite at the level of complexity of a quantum computer based on the experimental advances made so far, while one that still could perform some tasks that classical devices cannot, and much studies have been done on quantum simulation for constructing a quantum simulator. The aim of this dissertation is to design schemes of quantum information processing with solid-state systems or their hybrid systems based on the present available technologies and to study trapped-ion quantum simulation. The main contents are as follows:◆In the endohedral fullerenes system, we have proposed a potentially practical scheme to entangle spatially fullerene-based electron spins for distributed quantum information processing using optical and microwave manipulation. Assisted by the faster optical method and much less overhead, compared with previous works using nearest-neighbor coupling. Besides, we also have presented two scalable methods for generation of cluster states with arrays of endohedral fullerenes using direct and indirect methods, and analyzed the scalability.◆Quantum information can be protected by encoding qubits in decoherence-free subspace (DFS). Dual-rail representation can combat collective phase noise caused by random fluctuations. In the context of low-Q cavity QED, we have specifically designed a potentially practical scheme for realization of a multi-qubit Grover search algorithm with DFS encoding.◆Attribute to the clear environment and high controllability, trapped ions are among the most promising platforms for the quantum simulation of quantum physics. We have explored the Franck-Condon (FC) physics via a single ion confined in a spin-dependent potential, formed by the combination of a Paul trap and a magnetic field gradient. To the best of our knowledge, this has been the first proposal for observing the FC principle in a true single-particle system. In addition, for an array of trapped ions, we have presented the possibility of globally implementing a Heisenberg-limited Mach-Zehnder interferometry with a quantum transverse-field Ising model and nonlinear interactions, respectively, which is of potential application in quantum metrology of the ion trap system.