초록 |
Particles kicked by external forces to produce mobility distinct from thermal diffusion are an iconic feature of the active matter problem. Understanding this is central to the problem of swimming bacteria, active colloidal particles, and even catalytic enzymes. Here, we map this onto a minimal model for experiment and theory covering the wide time and length scales of usual active matter systems. A particle diffusing in a harmonic potential generated by optical trap is kicked by programmed forces that arrive at random intervals. The model’s generic simplicity allows us to find conditions for which displacements are Gaussian (or not), how diffusion is perturbed (or not) by kicks, and quantifying energy dissipation to maintain the non-equilibrium steady state. A further advantage is that active and thermal forces are varied independently as is impossible to achieve in most physical systems. |