Gaussification and entanglement distillation of continuous variable systems: a unifying picture

Abstract

Distillation of entanglement using only Gaussian operations is an important primitive in quantum communication, quantum repeater architectures, and distributed quantum computing. Existing distillation protocols for continuous degrees of freedom are only known to converge to a Gaussian state when measurements yield precisely the vacuum outcome. In sharp contrast, non-Gaussian states can be deterministically converted into Gaussian states while preserving their second moments, albeit by usually reducing their degree of entanglement. In this work - based on a novel instance of a non-commutative central limit theorem - we introduce a picture general enough to encompass the known protocols leading to Gaussian states, and new classes of protocols including multipartite distillation. This gives the experimental option of balancing the merits of success probability against entanglement produced.

4 + 4 pages, final version

References in corpus (6)

• Experimental entanglement distillation of mesoscopic quantum states
• High-fidelity entanglement swapping with fully independent sources
• Preparation of distilled and purified continuous variable entangled states
• Distillation and purification of symmetric entangled Gaussian states
• Iterative Entanglement Distillation: Approaching full Elimination of Decoherence
• On the experimental feasibility of continuous-variable optical entanglement distillation

Cited by in corpus (13)

• Strategies for enhancing quantum entanglement by local photon subtraction
• Repeaters for Continuous Variable Quantum Communication
• Continuous-variable entanglement distillation and non-commutative central limit theorems
• Magic-induced computational separation in entanglement theory
• Multi-step two-copy distillation of squeezed states via two photon subtraction
• Continuous-variable entanglement distillation by cascaded photon replacement
• Efficient entanglement distillation without quantum memory
• Continuous-variable quantum communication
• Rate limits in quantum networks with lossy repeaters
• Entanglement Enhancement in Multimode Integrated Circuits
• Theoretical framework for enhancing or enabling cooling of a mechanical resonator via the anti-Stokes or Stokes interaction and zero-photon detection
• Experimental investigation of heralded Gaussification of phase-randomized coherent states of light
• Simplified scheme for continuous-variable entanglement distillation: multicopy distillation of Gaussian entanglement without heralding Gaussian measurements