两类可观测量的Bell不等式

Bell Inequalities on Two Classes of Observables

引入了可观量a和ab关于密度矩阵ρ的平均值E_ρ(a)=Tr(aρ)与E_ρ(a,b)=Tr((ab)ρ),给出了一系列性质,建立了相应的Bell不等式|E_ρ(a,b)+E_ρ(a,c)+E_ρ(d,b)-E_ρ(d,c)|≤2(‖Pρn1‖2+‖Pρn2‖2)～(1/2)≤22^(1/2).

The expectations of two classes of observables a and a() b with respect to a density matrix p are defined as E_ρ(a) = Tr(ap) and E_ρ(a,b) = Tr((a()b)p) and some properties of them are obtained.Especially,corresponding Bell inequality is proved,which reads |E_ρ(a,b) +E_ρ(a,c)+E_ρ(d,b)-E_ρ(d,c)|≤2(‖Pρn1‖2+‖Pρn2‖2)～(1/2)≤22~1/2.