Realization of optimal disentanglement by teleportation via separable channels
Sibasish Ghosh, Guruprasad Kar, Anirban Roy, Debasis Sarkar, Ujjwal Sen · Physical Review A · 2001
We discuss optimal disentanglement processes of states of two two-level systems that belong to (i) the universal set, (ii) the set in which the states of one party lie on a single great circle of the Bloch sphere, and (iii) the set in which the states of one party commute with each other, by teleporting the states of one party (on which the disentangling machine is acting) through three particular types of separable channels, each of which is a mixture of Bell states. In the general scenario, by teleporting one party's state of an arbitrary entangled state of two two-level parties through some mixture of Bell states, we have shown that this entangled state can be made separable by using a physically realizable map $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{V}$ acting on one party's states, if $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{V}(I)=I,\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{V}({\ensuremath{\sigma}}_{j})={\ensuremath{\lambda}}_{j}{\ensuremath{\sigma}}_{j},$ where ${\ensuremath{\lambda}}_{j}>~0$ (for $j=1,2,3)$ and ${\ensuremath{\lambda}}_{1}+{\ensuremath{\lambda}}_{2}+{\ensuremath{\lambda}}_{3}<~1.$