Quantum benchmarks for pure single-mode Gaussian states

TL;DR

This paper establishes quantum benchmarks for the teleportation and storage of general pure single-mode Gaussian states, providing a basis for validating quantum network implementations beyond classical strategies.

Contribution

It introduces the first comprehensive benchmarks for arbitrary pure Gaussian states, including phase, displacement, and squeezing, with realistic prior distributions.

Findings

Fidelity benchmark for teleporting squeezed states with random phase and squeezing is 1/2.

Benchmarks for general pure Gaussian states are derived.

Entangled resources can surpass these benchmarks in experiments.

Abstract

Teleportation and storage of continuous variable states of light and atoms are essential building blocks for the realization of large scale quantum networks. Rigorous validation of these implementations require identifying, and surpassing, benchmarks set by the most effective strategies attainable without the use of quantum resources. Such benchmarks have been established for special families of input states, like coherent states and particular subclasses of squeezed states. Here we solve the longstanding problem of defining quantum benchmarks for general pure Gaussian single-mode states with arbitrary phase, displacement, and squeezing, randomly sampled according to a realistic prior distribution. As a special case, we show that the fidelity benchmark for teleporting squeezed states with totally random phase and squeezing degree is 1/2, equal to the corresponding one for coherent states. We discuss the use of entangled resources to beat the benchmarks in experiments.