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

Abstract

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 processes at finite temperature, for which the ultimately robust state remains entangled up to two times longer than conventional maximally entangled states.

9 pages, 3 figures, proof of Proposition 1 is corrected

References in corpus (11)

• Device-independent security of quantum cryptography against collective attacks
• Finite-Time Disentanglement via Spontaneous Emission
• Sudden Death of Entanglement
• Entanglement dynamics of two independent qubits in environments with and without memory
• A Factorization Law for Entanglement Decay
• Remote preparation of quantum states
• Manipulating sudden death of entanglement of two-qubit X-states in thermal reservoirs
• Entanglement-annihilating and entanglement-breaking channels
• Dynamics of entanglement of two electron spins interacting with nuclear spin baths in quantum dots
• PPT-inducing, distillation-prohibiting, and entanglement-binding quantum channels
• A statistical portrait of the entanglement decay of two-qubit memories

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