Boundary states for entanglement robustness under dephasing and bit flip channels*

Abstract

We investigate the robustness of entanglement for a multiqubit system under dephasing and bit flip channels. We exhibit the difference between the entanglement evolution of the two forms of special states, which are locally unitarily equivalent to each other and therefore possess precisely the same entanglement properties, and demonstrate that the difference increases with the number of qubits n. Moreover, those two forms of states are either the most robust genuine entangled states or the most fragile ones, which confirm that local unitary (LU) operations can greatly enhance the entanglement robustness of n-qubit states.

Robustness of multipartite entangled states for fermionic systems under noisy channels in non-inertial frames

“…Zhang et al [15] have systematically investigated the speed of disentanglement for twoqubit arbitrary states and three-qubit pure states under depolarizing channel and found that GHZ-type states are the most robust. Several studies [16][17][18][19][20] have been devoted to the investigation of the robustness of multiqubit states which are locally unitarily equivalent to each other and therefore initially contain the same amount of entanglement. Borras et al [16] have investigated the decay of entanglement of multiqubit states that are equivalent to GHZ states under local unitary transformations.…”

“…In each of these decoherence processes, they proved the most robust genuine tripartite entangled states and the most fragile ones. Li et al [18] have investigated the robustness of multiqubit states under dephasing and bit flip channels and showed the difference between the entanglement evolution of the states of the two special forms, which are locally unitarily equivalent to each other. Pan et al [19]…”

Tighter constraints of multiqubit entanglement in terms of Rényi-α entropy*

“…Quantum entanglement is one of the most quintessential features of quantum mechanics, which distinguishes the quantum world from the classical one and plays essential roles in quantum information processing, [1][2][3][4][5] revealing the basic understanding of the nature of quantum correlations. One distinct property of quantum entanglement is that a quantum system entangled with another system limits its sharing with other systems, known as the monogamy of entanglement.…”