Inertial active harmonic particle with memory escape induced by viscoelastic suspension

Abstract: We investigate the self-propulsion of an inertial active particle confined in a two-dimensional harmonic trap. The particle is suspended in a non-Newtonian or viscoelastic suspension with a friction kernel that decays exponentially with a time constant characterizing the memory timescale or transient elasticity of the medium. By solving the associated non-Markovian dynamics, we identify two regimes in parameter space distinguishing the oscillatory and non-oscillatory behavior of the particle motion. By simulating the particle trajectories and exactly calculating the steady state probability distribution functions and mean square displacement, interestingly, we observe that with an increase in the memory time scale, the elastic bound of suspension dominates over the influence of harmonic trap. As a consequence, the particle can escape out of the trap without approaching steady state. On the other hand, with an increase in the duration of the activity, the particle becomes trapped by the harmonic confinement.