Cooling nanorotors by elliptic coherent scattering

Electric trapping and circuit cooling of charged nanorotors

The motion of charged particles can be interfaced with electric circuitry via the current induced in nearby pick-up electrodes. Here we show how the rotational and translational dynamics of levitated objects with arbitrary charge distributions can be coupled to a circuit and how the latter acts back on the particle motion. The ensuing cooling rates in series and parallel RLC circuits are determined, demonstrating that quadrupole ion traps are well suited for implementing all-electric cooling. We derive the effective macromotion potential for general trap geometries and demonstrate numerically …

纳米陀螺两个摆动模式的量子基态冷却

Quantum ground-state cooling of two librational modes of a nanorotor

研究通过光学陷阱和高 finesse 腔体冷却纳米陀螺的两个摆动模式，实现量子基态，精度优于20微弧度。

Theory of nanoparticle cooling by elliptic coherent scattering

Coherent scattering of an elliptically polarised tweezer into a cavity mode provides a promising platform for cooling levitated nanoparticles into their combined rotational and translational quantum regime [Phys. Rev. Lett. 126, 163603 (2021)]. This article presents the theory of how aspherical nanoparticles are affected by elliptically polarised laser beams, how two orthogonal cavity modes enable rotational and translational cooling, and how the resulting power spectra contain signatures of rotational non-linearities. We provide analytic expressions for the resulting trapping frequencies, opt…

利用椭圆相干散射同时冷却光学悬浮纳米粒子的全部六个自由度

Simultaneous cooling of all six degrees of freedom of an optically levitated nanoparticle by elliptic coherent scattering

该研究利用高精细度光学腔中的椭圆相干散射，实现了高真空光镊悬浮纳米粒子全部六个平动与转动自由度的同时冷却和取向控制。

Coherent scattering 2D cooling in levitated cavity optomechanics

The strong light-matter optomechanical coupling offered by Coherent Scattering (CS) set-ups have allowed the experimental realisation of quantum ground state cavity cooling of the axial motion of a levitated nanoparticle [U. Delić et al., Science 367, 892 (2020)]. An appealing milestone is now quantum 2D cooling of the full in-plane motion, in any direction in the transverse plane. By a simple adjustment of the trap polarisation, one obtains two nearly equivalent modes, with similar frequencies $ω_{x}\simω_{y}$ and optomechanical couplings $g_{x}\simeq g_{y}$ -- in this experimental configurat…