制备三量子位和四量子位核磁共振等效纯态

Preparation of 3-qubit and 4-qubit pesudo-pure states in NMR quantum computation

基于时间平均法 ,给出了在同核系统中制备三量子位和四量子位核磁共振等效纯态的方案 .利用Λn(not)门 ,本文的方案大大减少了制备等效纯态所需的操作次数 :在三同核系统中制备三量子位核磁共振等效纯态只需三次操作 ,在四同核系统中制备四量子位核磁共振等效纯态只需五次操作 .然后在一个链状耦合的同核系统中实验制备三量子位核磁共振等效纯态 ,验证了本文的方案 ;

Basing on the temporal averaging, schedules to prepare 3-qubit and 4-qubit pesudo-pure states in nuclear magnetic resonance (NMR) quantum computation are presented in this paper. Utilizing Lambda(n) (not) gate, our schedules reduced the experiment number that is needed to prepare pesudo-pure state in a homonuclear spin system: only three experiments are needed to prepare 3-qubit peudo-pure state; and only five experiments are needed to prepare 4-qubit peudo-pure state. Then we implemented the schedule for 3-qubit psudo-pure state in a chain-coupled spin system to confirm the schedule, and gave the simulation result of the schedule for the 4-qubit peudo-pure state.