Quantum sensing with nanoparticles for gravimetry: when bigger is better

Abstract

Following the first demonstration of a levitated nanosphere cooled to the quantum ground state in 2020 (U. Delić, et al. Science, vol. 367, p. 892, 2020), macroscopic quantum sensors are seemingly on the horizon. The nanosphere’s large mass as compared to other quantum systems enhances the susceptibility of the nanoparticle to gravitational and inertial forces. In this viewpoint, we describe the features of experiments with optically levitated nanoparticles (J. Millen, T. S. Monteiro, R. Pettit, and A. N. Vamivakas, “Optomechanics with levitated particles,” Rep. Prog. Phys., vol. 83, 2020, Art no. 026401) and their proposed utility for acceleration sensing. Unique to the levitated nanoparticle platform is the ability to implement not only quantum noise limited transduction, predicted by quantum metrology to reach sensitivities on the order of 10−15 ms−2 (S. Qvarfort, A. Serafini, P. F. Barker, and S. Bose, “Gravimetry through non-linear optomechanics,” Nat. Commun., vol. 9, 2018, Art no. 3690) but also long-lived quantum spatial superpositions for enhanced gravimetry. This follows a global trend in developing sensors, such as cold-atom interferometers, that exploit superposition or entanglement. Thanks to significant commercial development of these existing quantum technologies, we discuss the feasibility of translating levitated nanoparticle research into applications.

Stern-Gerlach Interferometry for Tests of Quantum Gravity and General Applications

“…Inertial force-sensing and measurements of the fundamental constants of Nature: With the advent of light-pulse atom interferometry in recent years, there has been a considerable advance in the realization of precision interferometry-based approaches. It has become possible to design and/or construct quantum sensors and nanosphere matter-wave interferometers that enable inertial force-sensing at incredibly small length scales (for recent developments in this field, see [59][60][61]). An additional advantage that these sensors offer is the precise determination of the fundamental constants of Nature (see for instance [62]).…”

Can Traditional Terrestrial Applications of Gravity Gradiometry Rely Upon Quantum Technologies ? A Side View

“…Another interesting departure from either standard CAIs or BECs has been discussed in [Millen et al, 2020;Rademacher et al, 2020]. Following the first demonstration of a levitated nanosphere cooled to a quantum ground state [Delic et al, 2020], the authors discuss a macroscopic sensing "when bigger is better".…”

Master-equation treatment of nonlinear optomechanical systems with optical loss

“…Recent years have seen significant interest in the study of theoretical and experimental aspects of optomechanical systems [1]. In particular, the reported achievements of ground-state cooling [2][3][4] as well as the entanglement of macroscopic systems [5][6][7][8] have significantly improved the prospects for using optomechanical systems as sensors [9][10][11] and for tests of fundamental physics [12][13][14][15][16][17].…”