Coupling Modifies the Quantum Fluctuations of Entangled Oscillators

Abstract

© 2021, Sociedade Brasileira de Física.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 the quantum fluctuations of the coordinates and momenta of the oscillators in a single-excitation entangled Bell-like 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 for noise transfer may be explored in precision measurements in entanglement-assisted sensing and metrology.