Nonequilibrium fluctuations for a single-particle analog of gas in a soft wall.
We investigate the motion of a colloidal particle driven out of equilibrium by a time-varying stiffness of the optical trap that produces persistent nonequilibrium work. Measurements of work production for repeated cycles composed of the compression and expansion processes for the optical potential show huge fluctuations due to thermal motion. Using a precise technique to modulate the stiffness in time, we accurately estimate the probability distributions of work produced for the compression and expansion processes. We confirm the fluctuation theorem from the ratio of the two distributions. We also show that the average values of work for the two processes comply with the Jarzynski equality. This system has an analogy with a gas in a breathing soft wall. We discuss about its applicability to a heat engine and an information engine operated by feedback control.
Department of Physics, Pusan National University, Pusan 609-735, Korea and Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan 689-798, Korea.
Dong Yun
DY
Lee
Department of Physics, Myongji University, Gyeonggi-Do 449-728, Korea.
Chulan
C
Kwon
Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan 689-798, Korea and Department of Physics, Ulsan National Institute of Science and Technology, Ulsan 689-798, Korea.
Hyuk Kyu
HK
Pak