Simulations and theory of power spectral density functions for time dependent and anharmonic Langevin oscillators

Fuente: arXiv
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Main Authors: Amer, AbdAlGhaffar K., Robicheaux, F.
Format: Preprint
Published: 2023
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author Amer, AbdAlGhaffar K.
Robicheaux, F.
author_facet Amer, AbdAlGhaffar K.
Robicheaux, F.
contents Simulations and theory are presented for the power spectral density functions (PSDs) of particles in time dependent and anharmonic potentials including the effects of a thermal environment leading to damping and fluctuating forces. We investigate three one dimensional perturbations to the harmonic oscillator of which two are time dependent changes in the natural frequency of the oscillator, while the other is a time independent extension of the quadratic potential to include a quartic term. We investigate the effect of these perturbations on two PSDs of the motion that are used in experiments on trapped nano-oscillators. We also derive and numerically test the PSDs for the motion of a spherical nanoparticle in a Paul trap. We found that the simple harmonic Langevin oscillator's PSDs are good approximations for the $x$-and $y$-coordinates' PSDs for small values of the parameter $q$ of the Mathieu equation, but the difference can be more than a factor of two as '$q$' increases. We also numerically showed that the presence of a permanent electric dipole on the nanosphere can significantly affect the PSDs in the $x$-and $y$-coordinates.
format Preprint
id arxiv_https___arxiv_org_abs_2305_19260
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Simulations and theory of power spectral density functions for time dependent and anharmonic Langevin oscillators
Amer, AbdAlGhaffar K.
Robicheaux, F.
Applied Physics
Simulations and theory are presented for the power spectral density functions (PSDs) of particles in time dependent and anharmonic potentials including the effects of a thermal environment leading to damping and fluctuating forces. We investigate three one dimensional perturbations to the harmonic oscillator of which two are time dependent changes in the natural frequency of the oscillator, while the other is a time independent extension of the quadratic potential to include a quartic term. We investigate the effect of these perturbations on two PSDs of the motion that are used in experiments on trapped nano-oscillators. We also derive and numerically test the PSDs for the motion of a spherical nanoparticle in a Paul trap. We found that the simple harmonic Langevin oscillator's PSDs are good approximations for the $x$-and $y$-coordinates' PSDs for small values of the parameter $q$ of the Mathieu equation, but the difference can be more than a factor of two as '$q$' increases. We also numerically showed that the presence of a permanent electric dipole on the nanosphere can significantly affect the PSDs in the $x$-and $y$-coordinates.
title Simulations and theory of power spectral density functions for time dependent and anharmonic Langevin oscillators
topic Applied Physics
url https://arxiv.org/abs/2305.19260