In a recent letter [H.F. Wang, X. Ji, and S. Zhang, Phys. Lett. A 358 （2006） 11], an improvement of the multiparty quantum secret splitting and quantum state sharing protocol [F.G. Deng, et al., Phys. Lett. A 354 （...In a recent letter [H.F. Wang, X. Ji, and S. Zhang, Phys. Lett. A 358 （2006） 11], an improvement of the multiparty quantum secret splitting and quantum state sharing protocol [F.G. Deng, et al., Phys. Lett. A 354 （2006） 190.] was presented. We study the security of the improved protocol and find that two or more dishonest participants may recover the secret from the dealer. Hence we further modify the improved protocol, which make it stand against this kind of attack.展开更多
We present an efficient two-step entanglement concentration protocol(ECP)for three-level atoms trapped in one-sided optical micro-cavities in an arbitrary three-particle less-entangled W state,using the coherent state...We present an efficient two-step entanglement concentration protocol(ECP)for three-level atoms trapped in one-sided optical micro-cavities in an arbitrary three-particle less-entangled W state,using the coherent state input-output process in low-Q cavity quantum electrodynamics system.In each step of the new proposed protocol,one of the three remote users prepares the auxiliary coherent optical pulses to perform cavity input-output process and then utilizes the standard homodyne measurement to discriminate the final outgoing coherent states.When both of the two steps are successful,remote parties can deterministically concentrate the less-entangled W state atoms to a standard maximally entangled W state.Compared with previous ECPs for W state,this protocol has some advantages and can be widely used in current quantum repeater and some quantum information processing tasks.展开更多
基金Supported by National Natural Science Foundation of China under Grant No.60903152National Laboratory for Modern Communications Science Foundation of China under Grant No.9140C1101010601+3 种基金the Beijing Natural Science Foundation under Grant No.4072020a Key Project of Fujian Provincial Universities - Information Technology Research Based on Mathematics the Fujian Province Natural Science Foundation under Grant No.2008J0013the Foundation of Fujian Education Bureau under Grant No.JA08044
文摘In a recent letter [H.F. Wang, X. Ji, and S. Zhang, Phys. Lett. A 358 （2006） 11], an improvement of the multiparty quantum secret splitting and quantum state sharing protocol [F.G. Deng, et al., Phys. Lett. A 354 （2006） 190.] was presented. We study the security of the improved protocol and find that two or more dishonest participants may recover the secret from the dealer. Hence we further modify the improved protocol, which make it stand against this kind of attack.
基金supported by the National Fundamental Research Program of China(Grant No.2010CB923202)the Specialized ResearchFund for the Doctoral Program of Education Ministry of China(GrantNo.20090005120008)the National Natural Science Foundation ofChina(Grant Nos.61177085 and 61205117)
文摘We present an efficient two-step entanglement concentration protocol(ECP)for three-level atoms trapped in one-sided optical micro-cavities in an arbitrary three-particle less-entangled W state,using the coherent state input-output process in low-Q cavity quantum electrodynamics system.In each step of the new proposed protocol,one of the three remote users prepares the auxiliary coherent optical pulses to perform cavity input-output process and then utilizes the standard homodyne measurement to discriminate the final outgoing coherent states.When both of the two steps are successful,remote parties can deterministically concentrate the less-entangled W state atoms to a standard maximally entangled W state.Compared with previous ECPs for W state,this protocol has some advantages and can be widely used in current quantum repeater and some quantum information processing tasks.
