Fluctuation theorems are fundamental extensions of the second law of thermodynamics for small
nonequilibrium systems. While work and heat are equally important forms of energy exchange,
fluctuation relations have not been experimentally assessed for the generic situation of simultaneous
mechanical and thermal changes. Thermal driving is indeed generally slow and more dicult to
realize than mechanical driving. Here, we use feedback cooling techniques to implement fast and
controlled temperature variations of an underdamped levitated microparticle that are one order of
magnitude faster than the equilibration time. Combining mechanical and thermal control, we verify
the validity of a
uctuation theorem that accounts for both contributions, well beyond the range of
linear response theory. Our results allow the investigation of general far-from-equilibrium processes
in microscopic systems that involve fast mechanical and thermal changes at the same time.
Scientific Publication:
Markus Rademacher, Michael Konopik, Maxime Debiossac, David Grass, Eric Lutz, Nikolai Kiesel,"Nonequilibrium control of thermal and mechanical changes in a levitated system"
