Resolved-Sideband Cooling of a Levitated Nanoparticle in the Presence of Laser Phase Noise.

We investigate the influence of laser phase noise heating on resolved sideband cooling in the context of cooling the center-of-mass motion of a levitated nanoparticle in a high-finesse cavity. Although phase noise heating is not a fundamental physical constraint, the regime where it becomes the main limitation in Levitodynamics has so far been unexplored and hence embodies from this point forward the main obstacle in reaching the motional ground state of levitated mesoscopic objects with resolved sideband cooling. We reach minimal center-of-mass temperatures comparable to T_{min}=10  mK at a pressure of p=3×10^{-7}  mbar, solely limited by phase noise.

Unraveling the optomechanical nature of plasmonic trapping.

Noninvasive and ultra-accurate optical manipulation of nanometer objects has recently gained interest as a powerful tool in nanotechnology and biophysics. Self-induced back-action (SIBA) trapping in nano-optical cavities has the unique potential for trapping and manipulating nanometer-sized objects under low optical intensities. However, thus far, the existence of the SIBA effect has been shown only indirectly via its enhanced trapping performances.

Realization of nonequilibrium thermodynamic processes using external colored noise.

We investigate the dynamics of single microparticles immersed in water that are driven out of equilibrium in the presence of an additional external colored noise. As a case study, we trap a single polystyrene particle in water with optical tweezers and apply an external electric field with flat spectrum but a finite bandwidth of the order of kHz. The intensity of the external noise controls the amplitude of the fluctuations of the position of the particle and therefore of its effective temperature.

Crowding induces differences in the diffusion of thermophilic and mesophilic proteins: a new look at neutron scattering results.

The dynamical basis underlying the increased thermal stability of thermophilic proteins remains uncertain. Here, we challenge the new paradigm established by neutron scattering experiments in solution, in which the adaptation of thermophilic proteins to high temperatures lies in the lower sensitivity of their flexibility to temperature changes. By means of a combination of molecular dynamics and Brownian dynamics simulations, we report a reinterpretation of those experiments and show evidence that under crowding conditions, such as in vivo, thermophilic and homolog mesophilic proteins have diffusional properties with different thermal behavior.

Instabilities of the harmonic oscillator with fluctuating damping.

We investigate the instabilities of a linear damped oscillator due to fluctuations of the damping parameter. The fluctuations are driven either by Gaussian white noise or Poisson white noise (white shot noise). We consider three notions of stability.

Real-time detection of changes in the electrophoretic mobility of a single cell induced by hyperosmotic stress.

Living cells survive environmentally stressful conditions by initiating a stress response. We monitored changes in the electrophoretic mobility (EPM) of single, optically trapped yeast cells under hyperosmotic stress conditions using optical tweezers combined with a position detector. We studied the dynamics of the EPM stress response for cells at different phases of the cell cycle.