Robust multipartite quantum correlations without complex encodings

Abstract

One of the main challenges for the manipulation and storage of multipartite entanglement is its fragility under noise. We present a simple recipe for the systematic enhancement of the resistance of multipartite entanglement against any local noise with a privileged direction in the Bloch sphere. For the case of exact local dephasing along any given basis, and for all noise strengths, our prescription grants full robustness: Even states with exponentially decaying entanglement are mapped to states whose entanglement is constant. In contrast to previous techniques resorting to complex logical-qubit encodings, such enhancement is attained simply by performing local-unitary rotations before the noise acts. The scheme is therefore highly experimentally friendly, as it brings no overhead of extra physical qubits to encode logical ones. In addition, we show that, apart from entanglement, the resiliences of the relative entropy of quantumness and the usefulness as resources for practical tasks such as metrology and nonlocality-based protocols are equivalently enhanced.

4 pages + appendix, 3 figures

References in corpus (7)

• Multi-party entanglement in graph states
• All non-classical correlations can be activated into distillable entanglement
• Scaling laws for the decay of multiqubit entanglement
• Multiparticle entanglement under the influence of decoherence
• Stable macroscopic quantum superpositions
• Scalability of GHZ and random-state entanglement in the presence of decoherence
• Multipartite quantum nonlocality under local decoherence

Cited by in corpus (13)

• Fisher information under decoherence in Bloch representation
• Open-System Dynamics of Entanglement
• Effective noise channels for encoded quantum systems
• Does relativistic motion always degrade quantum Fisher information?
• Detecting nonlocality of noisy multipartite states with the CHSH inequality
• Enhanced Multi-Qubit Phase Estimation in Noisy Environments by Local Encoding
• Double-port measurements for robust quantum optical metrology
• Time-local optimal control for parameter estimation in the Gaussian regime
• Entanglement of a pair of quantum emitters via continuous fluorescence measurements: a tutorial
• Local Decoherence-free Macroscopic Quantum states
• Ancilla-assisted frequency estimation under phase covariant noises with Greenberger-Horne-Zeilinger states
• Preservation of entanglement in local noisy channels
• Enhancing entanglement and total correlations dynamics via local unitaries