Drift of suspended single-domain nanoparticles in a harmonically oscillating gradient magnetic field

We study the nonlinear dynamics of single-domain ferromagnetic nanoparticles in a viscous liquid induced by harmonically oscillating gradient magnetic field absence and presence static uniform field. Under some physically reasonable assumptions, we derive coupled set stiff ordinary differential equations for magnetization angle particle coordinate describing rotational translational motions nanoparticles. Analytical solutions these are determined near far from origin, their correctness is confirmed numerically. show that if absent, each nanoparticle periodic functions time. In contrast, makes aperiodic. this case, perform detailed analysis predict appearance drift motion (directed transport) calculate both analytically numerically velocity, its dependence on time model parameters, analyze physical origin phenomenon discuss potential biomedical applications.