The nonadiabatic conditional geometric phase shift in a coiled fiber system

The nonadiabatic conditional geometric phase gate is required in the topological quantum computation in order to overcome the conflict between the requirement of adiabatic condition(to avoid the severe distortion from the nonadiabaticity to the results) and the removal of decoherence effects. It was demonstrated that the effective Hamiltonian that describes the propagation of photon fields inside the coiled fiber is just the WangMatsumoto type of Hamiltonian. Thus, the coiled fiber system will automatically generate the nonadiabatic conditional geometric phase shift. In addition, it was shown that the dynamical phase(resulting from the effective Hamiltonian) acquired by the polarized photons vanishes, and the conditional initial state can be easily prepared only by controlling the initial wave vector of photons. In a word, the coiled fiber system can automatically satisfy the requirements and conditions, which were proposed by Wang and Matsumoto in order to create the nonadiabatic conditional geometric phase shift in their NMR scheme.