Experimental temporal quantum steering

TL;DR

This paper presents the first experimental demonstration of temporal quantum steering using photon polarization, showing its potential for secure quantum communication and verification of particle interactions.

Contribution

It provides the first experimental evidence of temporal steering and explores its application in quantum key distribution security testing.

Findings

Temporal steering verified via photon polarization measurements.

Violation of temporal steering inequalities demonstrated.

Implications for secure quantum communication protocols.

Abstract

Temporal steering is a form of temporal correlation between the initial and final state of a quantum system. It is a temporal analogue of the famous Einstein-Podolsky-Rosen (spatial) steering. We demonstrate, by measuring the photon polarization, that temporal steering allows two parties to verify if they have been interacting with the same particle, even if they have no information about what happened with the particle in between the measurements. This is the first experimental study of temporal steering. We also performed experimental tests, based on the violation of temporal steering inequalities, of the security of two quantum key distribution protocols against individual attacks. Thus, these results can lead to applications for secure quantum communications and quantum engineering.