中文摘要：

基于一种特殊的控制非门,实现多光子偏振态与单光子空间高维态之间的相互变换,使得对多光子偏振态的操作可以通过对单光子的操作来完成,由此可以实现任意多光子正定算符值测量和多光子任意幺正操作.这种实现方式是以一定概率完成的,但其效率要优于此前的方案,在目前的实验条件下是可行的.

英文摘要：

Based on a special controlled-NOT gate,a multi-photon state encoded in polarizations of photons could be transformed into the corresponding single photon qudit encoded in spatial mode.It will make the processing on multi-photon change into the operation on a single-photon,if the inverse transformation from a single photon qudit back to a multi-photon state could be realized also.Associated with linear optical multi-port interferometer for single-photon unitary operation,the positive-operator value measurement and the universal unitary operation for multi-photon state are realized.This approach is more efficient than the previous one with decomposition into two-qubit gates in the circuit-based quantum computation,and it is feasible with using the current experimental technology.