Optical Tweezers and Maxwell's Demon

Sammanfattning: Future nanoscale applications of Brownian motors will benefit from further development of stochastic thermodynamics, bridging the the properties of systems in non-equilibrium with those in equilibrium. This thesis presents the first step towards a device mimicking Maxwell's demon, which will be used for a study of systems out of equilibrium. It operates using an optical tweezer that is scanned rapidly in a line, generating an optical line trap in which a silica bead of 1 µm diffuses. The bead is confined in regions of the trap using regions of lower intensity regions as barriers, which are implemented in relation to the bead's position in the trap. Properties of these barriers are investigated by studying the diffusion of the bead following the barrier's implementation. The goal was to experimentally confirm the precise size of two generated barriers in order to find the closest distance a barrier may be implemented without affecting the bead's diffusion. The trap used proved too small to successfully do so, and instead focus was shifted towards an investigation of the intensity gradients of the barriers.