Nonequilibrium Control of Thermal and Mechanical Changes in a Levitated System

Area of Science:

• Thermodynamics
• Statistical Mechanics
• Microscopic Systems

Background:

• Fluctuation theorems extend the second law of thermodynamics to small, nonequilibrium systems.
• Experimental verification of fluctuation relations for simultaneous work and heat exchange is lacking.
• Thermal driving is typically slow and difficult to implement compared to mechanical driving.

Purpose of the Study:

• To experimentally assess fluctuation theorems under combined mechanical and thermal driving.
• To investigate the validity of fluctuation relations beyond linear response theory.
• To enable the study of far-from-equilibrium processes involving rapid energy exchange.

Main Methods:

• Utilized feedback cooling techniques for controlled temperature variations.
• Employed an underdamped levitated microparticle as the experimental system.
• Implemented temperature variations significantly faster than the system's equilibration time.

Main Results:

• Verified a fluctuation theorem accounting for both mechanical and thermal contributions.
• Demonstrated validity well beyond the linear response regime.
• Achieved temperature variations one order of magnitude faster than equilibration time.

Conclusions:

• The study provides experimental validation for fluctuation theorems under combined driving.
• This work opens avenues for studying complex nonequilibrium phenomena in microscopic systems.
• Fast, controlled thermal driving is achievable using feedback cooling techniques.