Non-equilibrium steady state of a driven levitated particle with feedback cooling

Abstract

Laser trapped nanoparticles have been recently used as model systems to study fundamental relations holding far from equilibrium. Here we study, both experimentally and theoretically, a nanoscale silica sphere levitated by a laser in a low density gas. The center of mass motion of the particle is subjected, at the same time, to feedback cooling and a parametric modulation driving the system into a non-equilibrium steady state. Based on the Langevin equation of motion of the particle, we derive an analytical expression for the energy distribution of this steady state showing that the average and variance of the energy distribution can be controlled separately by appropriate choice of the friction, cooling and modulation parameters. Energy distributions determined in computer simulations and measured in a laboratory experiment agree well with the analytical predictions. We analyse the particle motion also in terms of the quadratures and find thermal squeezing depending on the degree of detuning.

Submitted to the New Journal of Physics

References in corpus (3)

• Dynamic Relaxation of a Levitated Nanoparticle from a Non-Equilibrium Steady State
• Frequency and phase noise of ultra-high Q silicon nitride nanomechanical resonators
• Optimal operating points of oscillators using nonlinear resonators

Cited by in corpus (6)

• Auxiliary-cavity-assisted ground-state cooling of optically levitated nanosphere in the unresolved-sideband regime
• Multi-parameter estimation along quantum trajectories with Sequential Monte Carlo methods
• Single and two-mode mechanical squeezing of an optically levitated nanodiamond via dressed-state coherence
• Optomechanical oscillator controlled by variation in its heat bath temperature
• Single Particle Thermodynamics with Levitated Nanoparticles
• Relaxation to steady states of a binary liquid mixture around an optically heated colloid