Enhanced Lateral\nOptical Force Induced by Magnetic\nSpin–Orbit Interaction with Negligible Heat Generation

The optical lateral force acting on particles has sparked\nextensive\nresearch interest due to its underlying physics and promising applications.\nHowever, the application of the optical lateral force usually encounters\ntwo key challenges: its relatively small magnitude and significant\nJoule heating. In this work, we propose a novel approach to enhance\nthe optical lateral force while simultaneously minimizing Joule heating,\nwhich is achieved through the magnetic spin–orbit interaction\non a dielectric-metallic heterostructure. The magnitude of the optical\nlateral force is enhanced by 3 orders of magnitude through the enhanced\nmagnetic resonance due to the mirror-image interactions. Meanwhile,\nthe impact of the thermal effect on the optical lateral force is avoided\nby confining the electric field in the dielectric layer and suppressing\nthe electric field enhancement. Furthermore, the optical lateral force\nis robust in terms of the size and refractive index of manipulated\nobjects. It can also be obtained in a broad wavelength band. This\nscheme is beneficial for sorting particles and manipulating nanoscale\nobjects.