NMR Realization Of Nonadiabatic Holonomic Quantum In A Decoherence-free Subspace

After more than 30 years of development,quantum computation which based on the basic principles of quantum mechanics have made great progress.It is widely believed that the computing speed of quantum computation is faster than that of classical computation in some areas.But,there are two important obstacles to the physical realization of quantum computation.One is that quantum systems interact with the environment to make quantum systems decoherence,lose quantum information.The other is that the imperfections of quantum manipulation lead to errors in the quantum computation process.The dissertation for master's degree focuses on the key issue of how to combat environmental noise and control errors in actual quantum computation.This paper mainly includes the following two contents:·The dissertation for master's degree introduces a mixed unitary channel model that uses multiple unitary operation results to achieve a non-unitary process,and a feasible experimental scheme is designed to provide a simple and controllable method for the study of open system characteristics.·The experimental implementation nonadiabatic holonomic quantum logic gates which is encoded in a decoherence-free subspace(DFS).This scheme combines the fault-tolerant of DFS and the robustness of geometric phase operation,and gives the construction of single-loop and composite-loop nonadiabatic holonomic quantum gates in DFS.The single-loop and composite-loop single qubit nonadiabatic holonomic quantum gates and entanglement gate are implemented in the NMR quantum register,and the robustness of single qubit holonomic quantum gates is tested by quantum process tomography,which fully demonstrates the advantages of composite-loop nonadiabatic holonomic quantum gate.