高效实现针对光子丢失问题的容错量子计算

基于两个基本操作——控制路径操作和纠缠子,首先给出非破坏性多光子奇偶校验的实现.随后,将这些操作用于光学量子计算中光子丢失问题的处理.可以实现奇偶量子态的制备,以及单体操作与两体控制非操作,由此可以实现普适容错量子计算.不管是态制备还是门操作都是确定性的,同时方案的实现复杂度也要远低于此前的方案,对于辅助单光子资源的需求也降到很低的程度.并且实现过程中除奇偶校验外,不需要进行任何单光子探测,因此不会造成任何单光子的损失,最大限度地利用了光子资源.比之此前的线性光学方案,我们方案的确定性、高效性、简单性以及资源的高利用率等特点,使得方案更具可行性和更加适用于大规模量子计算.

Efficient realization of loss-tolerant optical quantum computation

Based on two element operations, called controlled-path gate and entangler, the non-destructive multi-photon parity check could be deterministically realized. With these operations, the realization of loss-tolerant optical quantum computation, including the generation of parity states, the realization of single-particle operation and two-particle CNOT operation, could be very simple but deterministic and highly efficient. Moreover, the character of detected free of single photons in the computation, except of the parity-check, will make the requirement of single-photon resources much relax. Compared with the former linear optical schemes, this scheme with cross-phase modulation is simpler but deterministic, and more efficient but with less resource, which will make it more feasible and suitable for large-scale quantum computation.