Towards Measuring the Maxwell–Boltzmann Distribution of a Single Heated Particle

• DOI: 10.3389/fphy.2021.669459
• Publication Date: 2021-06-24T08:41:50Z
• Authors: Xiaoya Su; Alexander Fischer; Frank Cichos
• Keywords: Particle (ecology); Mean squared displacement; Boltzmann constant

The Maxwell–Boltzmann distribution is a hallmark of statistical physics in thermodynamic equilibrium linking the probability density particle’s kinetic energies to temperature system that also determines its configurational fluctuations. This unique relation lost for Hot Brownian Motion, e.g., when particle constantly heated create an inhomogeneous surrounding liquid. While fluctuations this case can be described with effective temperature, it not all degrees freedom and suggested different at timescales. In work, we report on our progress measure Motion ballistic regime. We have constructed optical setup displacement temporal resolution 10 ns giving corresponding spatial about 23 pm 0.92 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m1"><mml:mrow><mml:mi>μ</mml:mi><mml:mtext>m</mml:mtext></mml:mrow></mml:math> PMMA water. Using gold-coated polystyrene (AuPS) 2.15 id="m2"><mml:mrow><mml:mi>μ</mml:mi><mml:mtext>m</mml:mtext></mml:mrow></mml:math> diameter determine mean squared over more than six orders magnitude time. Our data recovers trends long timescales, yet shows clear effects region hydrodynamic time tails.