Coupling modifies the quantum fluctuations of entangled oscillators

TL;DR

This paper investigates how coupling in entangled quantum oscillators influences their fluctuations, revealing a noise transfer mechanism that can reduce uncertainty in certain variables, with implications for quantum sensing.

Contribution

It uncovers a novel noise transfer mechanism caused by coupling, affecting quantum fluctuations and uncertainty relations in entangled oscillators.

Findings

Coupling enables noise transfer between coordinate and momentum pairs.

Uncertainty product can be lowered for one pair and increased for another.

Potential applications in entanglement-assisted sensing and metrology.

Abstract

Coupled oscillators are among the simplest composite quantum systems in which the interplay of entanglement and interaction may be explored. We examine the effects of coupling on fluctuations of the coordinates and momenta of the oscillators in a single-excitation entangled state. We discover that coupling acts as a mechanism for noise transfer between one pair of coordinate and momentum and another. Through this noise transfer mechanism, the uncertainty product is lowered, on average, relatively to its non-coupled level for one pair of coordinate and momentum and it is enhanced for the other pair. This novel mechanism may be explored in precision measurements in entanglement-assisted sensing and metrology.