Speaker
Description
After recalling some of the defining properties of the motion of classical active partices, I will introduce and characterize different models for an active quantum particle where activity arises from engineered dissipation-- specifically, from a suitably coupled nonequilibrium environment. These include a model of a particle moving on a lattice with coherent and dissipative hopping, as well as quantum generalizations of well-studied models of active behavior, such as the active Ornstein-Uhlenbeck process, run-and-tumble dynamics, and the active Brownian particle. Despite the different microscopic mechanisms at play, all these models display key features of active motion. Notably, a crossover from diffusive to active-diffusive behavior at long times, leading to an effective Péclet number, as well as a strong sensitivity to boundary conditions which, in the open quantum system context, arises from the Liouville skin effect. I will briefly discuss possible experimental realizations with superconducting circuits or cold gases, closing with perspectives for many-body effects in quantum active matter.
Talk based on
arXiv:2603.19094
by Jeanne Gipouloux, Matteo Brunelli, Leticia Cugliandolo, Rosario Fazio,
and Marco Schirò