Absolutely separating quantum maps and channels

作者：Filippov S N; Magadov K Yu; Jivulescu M A

来源：New Journal of Physics, 2017, 19(8): 083010.

DOI：10.1088/1367-2630/aa7e06

• entanglement
• absolute separability
• quantum channel
• quantum dynamical map
• depolarization

Absolutely separable states rho remain separable under arbitrary unitary transformations U rho U-dagger. By example of a three qubit system we show that in a multipartite scenario neither full separability implies bipartite absolute separability nor the reverse statement holds. The main goal of the paper is to analyze quantum maps resulting in absolutely separable output states. Such absolutely separating maps affect the states in a way, when no Hamiltonian dynamics can make them entangled afterwards. We study the general properties of absolutely separating maps and channels with respect to bipartitions and multipartitions and show that absolutely separating maps are not necessarily entanglement breaking. We examine the stability of absolutely separating maps under a tensor product and show that Phi(circle times N) is absolutely separating for any N if and only if Phi is the tracing map. Particular results are obtained for families of local unital multiqubit channels, global generalized Pauli channels, and combination of identity, transposition, and tracing maps acting on states of arbitrary dimension. We also study the interplay between local and global noise components in absolutely separating bipartite depolarizing maps and discuss the input states with high resistance to absolute separability.

• 出版日期2017-8-14