Experimental entanglement distillation of mesoscopic quantum states

TL;DR

This paper demonstrates the distillation of entanglement from mesoscopic quantum states affected by non-Gaussian noise, using linear optics and classical communication to probabilistically enhance entanglement after transmission through a lossy channel.

Contribution

It presents the first experimental realization of entanglement distillation for mesoscopic quantum states subjected to non-Gaussian noise in a lossy environment.

Findings

Successful probabilistic increase of entanglement after transmission

Use of linear optical components for distillation

Robustness against non-Gaussian noise in quantum communication

Abstract

The distribution of entangled states between distant parties in an optical network is crucial for the successful implementation of various quantum communication protocols such as quantum cryptography, teleportation and dense coding [1-3]. However, owing to the unavoidable loss in any real optical channel, the distribution of loss-intolerant entangled states is inevitably inflicted by decoherence, which causes a degradation of the transmitted entanglement. To combat the decoherence, entanglement distillation, which is the process of extracting a small set of highly entangled states from a large set of less entangled states, can be used [4-14]. Here we report on the mesoscopic distillation of deterministically prepared entangled light pulses that have undergone non-Gaussian noise. The entangled light pulses [15-17] are sent through a lossy channel, where the transmission is varying in time similarly to light propagation in the atmosphere. By employing linear optical components and global classical communication, the entanglement is probabilistically increased.