Home
About/Contact
Newsletters
Events/Seminars
2020 IPS Conference
Study Materials
Corporate Members
Collective excitations of hydrodynamically coupled driven colloidal particles
Harel Nagar , Yael Roichman
Department of physical chemistry Tel aviv univesity
Two colloidal particles, driven around an optical vortex trap, have been recently shown to pair due to an interplay between hydrodynamic interactions and the curved path they are forced to follow. We demonstrate here, that this pairing interaction can be tuned experimentally. We study its effect on the collective excitations of many particles driven around such an optical trap. We find that even though the system is overdamped, hydrodynamic interactions due to driving give rise to non-decaying excitations with characteristic dispersion relations. The collective excitations of the colloidal ring reflect fluctuations of particle pairs rather than those of single particles.