Einstein-Podolsky-Rosen paradox and quantum steering in pulsed optomechanics

TL;DR

This paper explores how to generate and analyze EPR paradoxes and quantum steering in pulsed optomechanical systems, revealing thermal barriers and asymmetries in quantum nonlocality involving mesoscopic oscillators and optical pulses.

Contribution

It introduces a method to generate EPR paradoxes in pulsed optomechanics and analyzes the impact of thermal noise and asymmetry on quantum nonlocality.

Findings

Thermal barrier exists for oscillator-based EPR paradoxes.

No thermal barrier for pulse-oscillator entanglement.

Asymmetry in thermal noise effects on quantum nonlocality.

Abstract

We describe how to generate an Einstein-Podolsky-Rosen (EPR) paradox between a mesoscopic mechanical oscillator and an optical pulse. We find two types of paradox, defined by whether it is the oscillator or the pulse that shows the effect Schrodinger called "steering". Only the oscillator paradox addresses the question of mesoscopic local reality for a massive system. In that case, EPR's "elements of reality" are defined for the oscillator, and it is these elements of reality that are falsified (if quantum mechanics is complete). For this sort of paradox, we show that a thermal barrier exists, meaning that a threshold level of pulse-oscillator interaction is required for a given thermal occupation n_0 of the oscillator. We find there is no equivalent thermal barrier for the entanglement of the pulse with the oscillator, nor for the EPR paradox that addresses the local reality of the optical system. Finally, we examine the possibility of an EPR paradox between two entangled oscillators. Our work highlights the asymmetrical effect of thermal noise on quantum nonlocality.