Free-energy inference from partial work measurements in small systems.

ABSTRACT: Fluctuation relations (FRs) are among the few existing general results in nonequilibrium systems. Their verification requires the measurement of the total work performed on a system. Nevertheless in many cases only a partial measurement of the work is possible. Here we consider FRs in dual-trap optical tweezers where two different forces (one per trap) are measured. With this setup we perform pulling experiments on single molecules by moving one trap relative to the other. We demonstrate that work should be measured using the force exerted by the trap that is moved. The force that is measured in the trap at rest fails to provide the full dissipation in the system, leading to a (incorrect) work definition that does not satisfy the FR. The implications to single-molecule experiments and free

SUBMITTER: Ribezzi-Crivellari M 

PROVIDER: S-EPMC4143063 | biostudies-literature | 2014 Aug

REPOSITORIES: biostudies-literature