基于原子系综系统实现Controlled-Hadamard 门和制备多量子比特的W-type态

提出了利用Rydberg阻滞机制，实现基于原子系综系统的控制Hadamard门和制备n个量子比特W-type态的方案.在该方案中，选取Rydberg态为激发态,其是1个辅助态，2个基态作为编码态. 由于控制Hadamard 门实现的操作时间比激发态的寿命小得多,因此，激发态的衰减效应可以忽略不计. 该方案可以得到高保真度的n个量子比特W-type态，且该方案在量子信息处理方面具有可扩展性.

IMPLEMENTATION OF CONTROLLED-HADAMARD GATE AND GENERATION OF W-TYPE STATE BASED ON ATOMIC ENSEMBLES

A Controlled-Hadamard gate based on the Rydberg blockade mechanism is constructed, and the n-qubit W-type state by using the Controlled-Hadamard gate and C-NOT gate is prepared. The Rydberg state is chosen as the excited state (an assistant state), and the two ground states are chosen to store information. The effect of the decay of the excited state can be neglected, because the implement time of the gate operation is much shorter than the lifetime of the ground state. A large number of atomic ensembles W-type states can be obtained by this scheme. This method also provides a way for the realization of scalable quantum computation.