Quantum Benchmark for Teleportation and Storage of Squeezed States

TL;DR

This paper establishes a quantum benchmark for teleporting and storing squeezed states, setting fidelity thresholds to distinguish quantum performance from classical strategies, and discusses implications for recent experiments.

Contribution

It introduces a fidelity benchmark for quantum teleportation and storage of squeezed states, including bounds for mixed states, aiding the evaluation of experimental quantum protocols.

Findings

Fidelity >81.5% surpasses classical strategies for pure states.

Derived bounds for classical fidelity with mixed squeezed thermal states.

Provides criteria to assess recent experimental achievements.

Abstract

We provide a quantum benchmark for teleportation and storage of single-mode squeezed states with zero displacement and a completely unknown degree of squeezing along a given direction. For pure squeezed input states, a fidelity higher than 81.5% has to be attained in order to outperform any classical strategy based on an estimation of the unknown squeezing and repreparation of squeezed states. For squeezed thermal input states, we derive an upper and a lower bound on the classical average fidelity which tighten for moderate degree of mixedness. These results enable a critical discussion of recent experiments with squeezed light.