Teleportation transfers only speakable quantum information

TL;DR

This paper demonstrates that teleporting a quantum clock without prior synchronization introduces unavoidable errors, but entanglement can still enhance synchronization precision beyond classical limits, applicable to various quantum reference frames.

Contribution

It establishes fundamental limits on teleporting unspeakable quantum information like clocks and shows how entanglement can improve synchronization accuracy.

Findings

Teleportation of quantum clocks necessarily introduces errors without prior synchronization.

Entanglement enables synchronization with precision surpassing classical correlations.

Results extend to continuous quantum reference frames conveying unspeakable information.

Abstract

We show that a quantum clock cannot be teleported without prior synchronization between sender and receiver: every protocol using a finite amount of entanglement and an arbitrary number of rounds of classical communication will necessarily introduce an error in the teleported state of the clock. Nevertheless, we show that entanglement can be used to achieve synchronization with precision higher than any classical correlation allows, and we give the optimized strategy for this task. The same results hold also for arbitrary continuous quantum reference frames, which encode general unspeakable information,-information that cannot be encoded into a number, but instead requires a specific physical support, like a clock or a gyroscope, to be conveyed.