Coherent oscillations of a levitated birefringent microsphere in vacuum driven by nonconservative rotation-translation coupling

Abstract

We demonstrate an effect whereby stochastic, thermal fluctuations combine with nonconservative optical forces to break detailed balance and produce increasingly coherent, apparently deterministic motion for a vacuum-trapped particle. The particle is birefringent and held in a linearly polarized Gaussian optical trap. It undergoes oscillations that grow rapidly in amplitude as the air pressure is reduced, seemingly in contradiction to the equipartition of energy. This behavior is reproduced in direct simulations and captured in a simplified analytical model, showing that the underlying mechanism involves nonsymmetric coupling between rotational and translational degrees of freedom. When parametrically driven, these self-sustained oscillators exhibit an ultranarrow linewidth of 2.2 μHz and an ultrahigh mechanical quality factor in excess of 2 × 108 at room temperature. Last, nonequilibrium motion is seen to be a generic feature of optical vacuum traps, arising for any system with symmetry lower than that of a perfect isotropic microsphere in a Gaussian trap.

Five-dimensional cooling and nonlinear dynamics of an optically levitated nanodumbbell

“…In recent years, levitated optomechanics provided a fruitful platform for nonequilibrium thermodynamics [1][2][3][4][5], nonlinear dynamics [6][7][8], precision measurements [9][10][11][12][13][14][15][16], macroscopic quantum mechanics [17][18][19], and several other applications [20][21][22]. Besides extensive studies on levitated spherical particles, there is growing interest in levitated nonspherical particles [23][24][25][26][27][28][29][30][31][32][33][34][35].…”

Optical trapping with structured light: a review

“…[249][250][251][252][253] There is no doubt that new developments in structured light beams will continuously boost the fields of optical manipulation. 254 Moreover, among the diverse optical trapping schemes discussed in this review, in our view, several topics have great potential to find exciting future applications, such as the optical trapping of metal particles [183][184][185][186][187][188][189] and chiral particles, 52,53 vacuum levitation, structured light in waveguides, [255][256][257][258][259] optical binding and other collective motions in structured light fields, 113,185,[260][261][262] quantum optomechanics, 30 and optical trapping for multidisciplinary applications. 32 In the future, besides SLMs and DMDs, more flexible, efficient and much less expensive devices will be developed to produce structured beams, which can help build the next generation of optical trapping technology.…”

Spin-Mechanics with Nitrogen-Vacancy Centers and Trapped Particles

“…For instance, in Paul traps, if the charge distribution has a non-zero dipole component, the center of mass and the angle may become coupled [76]. Similarly, shape anisotropy or birefringence of optically trapped particles can also induce a mode coupling [77,78]. These mechanisms are neglected here, but can be of interest for transferring the quantum state of one spin-coupled mode to another one.…”