Erasable and unerasable correlations

Abstract

We address the problem of removing correlation from sets of states while preserving as much local quantum information as possible. We prove that states obtained from universal cloning can only be decorrelated at the expense of complete erasure of local information (i.e. information about the copied state). We solve analytically the problem of decorrelation for two qubits and two qumodes (harmonic oscillators in Gaussian states), and provide sets of decorrelable states and the minimum amount of noise to be added for decorrelation.

4 pages, 2 figures

References in corpus (4)

• Asymptotic quantum cloning is state estimation
• Non-linear operations in quantum information theory
• Superbroadcasting of mixed states
• State estimation on correlated copies

Cited by in corpus (9)

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• Correlation Picture Approach to Open-Quantum-System Dynamics
• Broadcasting of continuous variable entanglement
• Optimal convex approximations of quantum states
• Private quantum decoupling and secure disposal of information
• Complete Optimal Convex Approximations of Qubit States under $B_2$ Distance
• Near-unit fidelity entanglement distribution using Gaussian communication
• Quantum state decorrelation
• The Quantum Cocktail Party Problem