Optomechanical sensor can suppress quantum noise and simultaneously amplify the input signal

Researchers have sought to detect very weak signals whose power is smaller than both the classical noises and quantum noises in nature. Such measurements would provide a promising tool to test quantum mechanics, decoherence mechanisms, and gravitational physics. Motazadeifard et al. report a hybridized optomechanical sensor that can suppress the quantum noise and amplify the input signal to a high extent.

“We introduced a hybrid optomechanical system equipped with an ensemble of ultracold atoms, known as a Bose-Einstein condensate, as an ultraprecision quantum sensor,” said author Ali Motazedifard. This sensor had a precision beyond the standard quantum limit, which is determined by the quantum mechanical behavior of the nature.

The researchers investigated three methods to cope with the challenge of ultraprecision quantum measurement. They examined how to cancel the quantum noise, how to evade the back-action noise of measurement, and how to suppress the quantum noise and simultaneously amplify the input signal.

To solve the challenge of suppressing the intrinsic quantum noises, while simultaneously amplifying the signal, the team proposed a method based on adding extra nonlinearities into the optomechanical system as an on-chip or integrated amplifier sensor. The proposed nonlinear sensor is hybridized through an ultracold atomic ensemble that provides a platform towards integrated ultrasensitive devices, such as force sensors or standard quantum clocks.

“These devices play a key role in a variety of fields of quantum technologies, such as communications, metrology and computing,” said Motazedifard. The introduced methods can also be applied for magnetometry, thermometry, gravimetry, and in other sensing schemes, such as levitated systems, circuit-optomechanics and atomic systems.

Source: “Ultra-precision quantum sensing and measurement based on nonlinear hybrid optomechanical systems containing ultracold atoms or atomic-Bose–Einstein condensate,” by Ali Motazedifard, A. Dalafi, and M. H. Naderi, AVS Quantum Science (2021). The article can be accessed at https://doi.org/10.1116/5.0035952 .

This paper is part of the Special Topic: Quantum Sensing and Metrology Collection, learn more here .