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Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
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Double Mpemba effect in the cooling of trapped colloids
Isha Malhotra1, Hartmut Löwen1
1Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany.
The Journal of Chemical Physics
|October 22, 2024
Summary
The Mpemba effect shows hot water cooling faster than cold. This study reveals a "Double Mpemba effect" in colloidal particle freezing, with cooling time decreasing twice with initial temperature.
Area of Science:
- Physics
- Physical Chemistry
- Colloid Science
Background:
- The Mpemba effect, where hotter water cools faster than colder water, is a counterintuitive phenomenon.
- This effect has been observed in various systems, including recent predictions and realizations for trapped colloids.
Purpose of the Study:
- To investigate the freezing behavior of a passive colloidal particle.
- To explore anomalous cooling rates and identify new phenomena beyond the standard Mpemba effect.
Main Methods:
- Numerical Brownian dynamics simulations.
- Theoretical calculations using an experimentally testable model.
- Application of machine-learning methods for data analysis.
Main Results:
- Observed multiple non-monotonic regimes in cooling rates for colloidal particles.
- Discovered the
- Double Mpemba effect,
- where cooling time decreases twice with increasing initial temperature.
- Demonstrated that both Mpemba and Double Mpemba effects can be predicted using machine learning.
Conclusions:
- The study reveals a novel
- Double Mpemba effect
- in colloidal freezing.
- Machine learning effectively predicts complex cooling behaviors, accelerating scientific discovery in computationally intensive systems.
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