Ultimate entanglement robustness of two-qubit states against general local noises

  title={Ultimate entanglement robustness of two-qubit states against general local noises},
  author={Sergey N. Filippov and Vladimir V. Frizen and Daria V. Kolobova},
  journal={Physical Review A},
We study the problem of optimal preparation of a bipartite entangled state, which remains entangled the longest time under action of local qubit noises. We show that for unital noises, such a state is always maximally entangled, whereas for nonunital noises, it is not. We develop a decomposition technique relating nonunital and unital qubit channels, based on which we find the explicit form of the ultimately robust state for general local noises. We illustrate our findings by amplitude damping… Expand

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