One-shot entanglement generation over long distances in noisy quantum networks

TL;DR

This paper proposes a one-shot method for establishing long-distance entanglement in noisy quantum networks using local encoding and network correction, avoiding the need for long quantum memories.

Contribution

It introduces a novel one-shot entanglement generation protocol that tolerates noise and scales logarithmically with network size, unlike traditional quantum repeaters.

Findings

Entanglement can be shared if error probability is below a threshold.

The method does not require long quantum memories due to one-way classical communication.

Overhead increases logarithmically with network size.

Abstract

We consider the problem of creating a long-distance entangled state between two stations of a network, where neighboring nodes are connected by noisy quantum channels. We show that any two stations can share an entangled pair if the effective probability for the quantum errors is below a certain threshold, which is achieved by using local redundant encoding to preserve the global phase and network-based correction for the bit-flip errors. In contrast to the convensional quantum repeater schemes we are not limited by the memory coherence time, because all quantum operations only use one-way classical communication and can be done in one shot. Meanwhile, the overhead of local resources only increases logarithmically with the size of the network, making our proposal favorable to practical applications of long-distance quantum communication.