Observation of one-way Einstein-Podolsky-Rosen steering

TL;DR

This paper reports the experimental demonstration of one-way Einstein-Podolsky-Rosen steering in entangled Gaussian light modes, revealing asymmetric quantum correlations that could impact quantum information applications.

Contribution

First experimental realization of one-way EPR steering with Gaussian light, highlighting directional quantum correlations not previously observed.

Findings

Demonstrated one-way steering between entangled light modes

Confirmed asymmetry in quantum steering phenomena

Provides new insights into quantum nonlocality and potential applications

Abstract

The distinctive non-classical features of quantum physics were first discussed in the seminal paper by A. Einstein, B. Podolsky and N. Rosen (EPR) in 1935. In his immediate response E. Schr\"odinger introduced the notion of entanglement, now seen as the essential resource in quantum information as well as in quantum metrology. Furthermore he showed that at the core of the EPR argument is a phenomenon which he called steering. In contrast to entanglement and violations of Bell's inequalities, steering implies a direction between the parties involved. Recent theoretical works have precisely defined this property. Here we present an experimental realization of two entangled Gaussian modes of light by which in fact one party can steer the other but not conversely. The generated one-way steering gives a new insight into quantum physics and may open a new field of applications in quantum information.