Quantum Brownian motion of a particle from Casimir-Polder interactions

Abstract

We study the fluctuation-induced dissipative dynamics of the quantized center of mass motion of a polarizable dielectric particle trapped near a surface. The particle's center of mass is treated as an open quantum system coupled to the electromagnetic field acting as its environment, with the resulting system dynamics described by a quantum Brownian motion master equation. The dissipation and decoherence of the particle's center of mass are characterized by the modified spectral density of the electromagnetic field that depends on surface losses and the strength of the classical trap field. Our results are relevant to experiments with levitated dielectric particles near surfaces, illustrating potential ways of mitigating fluctuation-induced decoherence while preparing such systems in macroscopic quantum states.

Real-time optimal quantum control of mechanical motion at room temperature

“…where ρ(n + ∆n) the population density of occupation n + ∆n state of the particle motion and M n,n+∆n the transition matrix element given by the cross term in the dipole-field interaction [78,79]:…”

Dissipative dynamics of a particle coupled to field via internal degrees of freedom

“…Furthermore, considering the zero-temperature limit of the dynamics, we find that a mechanical oscillator interacting with the vacuum field exhibits dissipative dynamics as a result of the quantum fluctuations of its composite nonlinear environment. Such a vacuum-induced noise poses a fundamental constraint on preparing mechanical objects in quantum states [29,30].…”

Surface-induced decoherence and heating of charged particles

“…This supports that the noise originates from a thin surface layer. In addition, macroscopic quantum electrodynamics has been employed to quantitatively describe the decoherence of fast electrons [74,88], of spins [94], and of the center-of-mass motion of magnetic [95] and polarizable [96] spheres above surfaces.…”

“…Non-rigid charge distributions-The fact that the bound charges inside the particle can fluctuate and react to fields emanating from the surface can be included in terms of the particle polarization. This adds to the dynamics (i) the Casimir-Polder interaction between the particle and the surface [91] as well as (ii) the associated decoherence channel [96]. This effect is expected to become relevant for weakly-charged micron-sized dielectrics.…”