Contact details Research Interests Quantum ratchets based on semiconductor nanostructures. Physics of motor proteins in biological systems. Classical and quantum effects in electron billiards.
Ratchets are devices that can make particles flow in one direction without any macroscopic forces.
Some molecular motors in biological systems are also thought to make use of ratchet effects. In general, one means by a 'ratchet' any sort of asymmetric potential. The second law of thermodynamics says that, as long as the system is left alone and remains in thermal equilibrium, particles in a ratchet can not diffuse in any preferential direction, in spite of the spatial asymmetry. When the system is driven away from thermal equilibrium, however, for instance if the ratchet potential changes with time, then the particles in the ratchet will in general start to move in one direction. The 'flashing ratchet' above is only one example for how this can work.