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Stochastic force dynamics of the model microswimmer Chlamydomonas reinhardtii: Active forces and energetics
Authors:
Corbyn Jones,
Mauricio Gomez,
Ryan M. Muoio,
Alex Vidal,
Anthony Mcknight,
Nicholas D. Brubaker,
Wylie W. Ahmed
Abstract:
We study the stochastic force dynamics of a model microswimmer (Chlamydomonas reinhardtii), using a combined experimental, theoretical, and numerical approach. While swimming dynamics have been extensively studied using hydrodynamic approaches, which infer forces from the viscous flow field, we directly measure the stochastic forces generated by the microswimmer using an optical trap via the photo…
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We study the stochastic force dynamics of a model microswimmer (Chlamydomonas reinhardtii), using a combined experimental, theoretical, and numerical approach. While swimming dynamics have been extensively studied using hydrodynamic approaches, which infer forces from the viscous flow field, we directly measure the stochastic forces generated by the microswimmer using an optical trap via the photon momentum method. We analyze the force dynamics by modeling the microswimmer as a self-propelled particle, a la active matter, and analyze it's energetics using methods from stochastic thermodynamics. We find complex oscillatory force dynamics and power dissipation on the order of $10^6$ $k_B T / s$ ($\sim$ fW)
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Submitted 5 February, 2021; v1 submitted 24 November, 2020;
originally announced November 2020.
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Quantifying the non-equilibrium activity of an active colloid
Authors:
Sarah Eldeen,
Ryan Muoio,
Paris Blaisdell-Pijuan,
Ngoc La,
Mauricio Gomez,
Alex Vidal,
Wylie Ahmed
Abstract:
Active matter systems exhibit rich emergent behavior due to constant injection and dissipation of energy at the level of individual agents. Since these systems are far from equilibrium, their dynamics and energetics cannot be understood using the framework of equilibrium statistical mechanics. Recent developments in stochastic thermodynamics extend classical concepts of work, heat, and energy diss…
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Active matter systems exhibit rich emergent behavior due to constant injection and dissipation of energy at the level of individual agents. Since these systems are far from equilibrium, their dynamics and energetics cannot be understood using the framework of equilibrium statistical mechanics. Recent developments in stochastic thermodynamics extend classical concepts of work, heat, and energy dissipation to fluctuating non-equilibrium systems. We use recent advances in experiment and theory to study the non-thermal dissipation of individual light-activated self-propelled colloidal particles. We focus on characterizing the transition from thermal to non-thermal fluctuations and show that energy dissipation rates on the order of $\sim k_BT/$s are measurable from finite time series data.
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Submitted 9 April, 2020;
originally announced April 2020.
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One Dimensional 1H, 2H and 3H
Authors:
A. J. Vidal,
G. E. Astrakharchik,
L. L. Vranješ Markić,
J. Boronat
Abstract:
The ground-state properties of one-dimensional electron-spin-polarized hydrogen $^1$H, deuterium $^2$H, and tritium $^3$H are obtained by means of quantum Monte Carlo methods. The equations of state of the three isotopes are calculated for a wide range of linear densities. The pair correlation function and the static structure factor are obtained and interpreted within the framework of the Lutting…
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The ground-state properties of one-dimensional electron-spin-polarized hydrogen $^1$H, deuterium $^2$H, and tritium $^3$H are obtained by means of quantum Monte Carlo methods. The equations of state of the three isotopes are calculated for a wide range of linear densities. The pair correlation function and the static structure factor are obtained and interpreted within the framework of the Luttinger liquid theory. We report the density dependence of the Luttinger parameter and use it to identify different physical regimes: Bogoliubov Bose gas, super-Tonks-Girardeau gas, and quasi-crystal regimes for bosons; repulsive, attractive Fermi gas, and quasi-crystal regimes for fermions. We find that the tritium isotope is the one with the richest behaviour. Our results show unambiguously the relevant role of the isotope mass in the properties of this quantum system.
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Submitted 27 May, 2016;
originally announced May 2016.