Optical trapping of nanoparticles in superfluid helium

Abstract

Optical tweezers, the three-dimensional confinement of a nanoparticle by a strongly focused beam of light, have been widely employed in investigating biomaterial nanomechanics, nanoscopic fluid properties, and ultrasensitive detections in various environments such as inside living cells, at gigapascal pressure, and under high vacuum. However, the cryogenic operation of solid-state-particle optical tweezers is poorly understood. In this study, we demonstrate the optical trapping of metallic and dielectric nanoparticles in superfluid helium below 2 K, which is two orders of magnitude lower than in the previous experiments. We prepare the nanoparticles via in-situ laser ablation. The nanoparticles are stably trapped with a single laser beam tightly focused in the superfluid helium. Our method provides a new approach for studying nanoscopic quantum hydrodynamic effects and interactions between quantum fluids and classical objects.

References in corpus (6)

• Optical alignment and spinning of laser-trapped microscopic particles
• Millikelvin cooling of an optically trapped microsphere in vacuum
• Calibration of optical tweezers with positional detection in the back-focal-plane
• Characterization of reconnecting vortices in superfluid helium
• Optical levitation of microdroplet containing a single quantum dot
• Brownian motion in superfluid ${}^4$He

Cited by in corpus (1)

• Visualisation of quantised vortex reconnection as enabled by laser ablation