EPR粒子对与量子隐形传态

量子隐形传态,由发送者Alice将准备传送的信息分离成一部分纯粹经典的信息和另外一部分纯粹非经典的信息,通过2条不同的信道传送给接收者Bob。首先传送非经典部分,这需要借助于EPR粒子对,考虑由2个自旋皆为12的费密子构成,其中一个分配给Alice,另一个分配给Bob。Alice选择对她一方的原始粒子和她的EPR粒子一并进行冯.罗曼类型的测量,这个在贝尔算符的4个本征态中的测量,导致系统的波函数的波包坍缩为相互关联的4个贝尔基矢。Bob通过对他的EPR粒子的状态进行适当的幺正变换,能够重新构造出在Alice一方被＂毁灭＂了的原始粒子的状态。此外,这个贝尔测量产生2个比特的经典信息,传送给Bob,从而完成一个量子隐形传态。文章中研究了EPR粒子对与量子隐形传态的内在联系。

EPR pairs of particles and quantum teleportation

Teleporting a quantum state,the sender Alice disassembles the entire informations into two parts： one purely classical information and the another purely non-classical information,then sends them to the receiver Bob via two different channels.Firstly,sending the purely non-classical part,the EPR pair which consists of two fermions with the spin of 1 2 here plays the key role in the teleportation,one EPR particle is given to Alice,while the other is given to Bob.Alice performs a complete measurement of the von Neumann type on the joint system consisting of the original particle and her EPR particle,this measurement performed in the four eigenstates of the Bell operator leads to ＂collapse＂ the wave packet of the joint wavefunction into the four correlated Bell bases.Through applying the appropriate unitary transformation to the state of his EPR particle Bob can reconstruct a replica of the original state ＂destroyed＂ in Alice＇s hand.Moreover,this Bell measurement produces two bits of classical information which is sent to Bob,a quantum teleportation is therefore completed.The paper studies the interior relation between EPR pairs of particles and the quantum teleportation.