Silicon photonic chips for search on improved glued binary tree based on continuous time quantum walk

Search on improved-glued-binary-trees is a representative example of quantum superiority, where exponential acceleration can be achieved using quantum walk with respect to any classical algorithms. Here we analyzed the evolution process of this quantum-walk-based algorithm. Several remarkable features of the process are revealed. Generation of the model by introducing tunable defect strength and double defects is also discussed and the effects of these generalization on evolution process, arrival probability and residual probability are discussed in details. Physical implementation with silicon ridge waveguide array is presented. The design of the array with FEM method are presented and light propagation simulation with FDTD method shows that this kind of structure is feasible for the task. Lastly, preliminary experimental demonstration with classical coherent light simulation are presented. Our results show that silicon photonic chips are suitable for such search problems and opening a route towards large-scale photonic quantum computation.