Conceptually new mechanism for trapping neutral, polar particles

TL;DR

This paper introduces a novel trapping mechanism using a superposition of static and oscillating electric monopole fields to trap particles with permanent electric dipoles, differing from traditional multipole traps.

Contribution

The paper presents the first analytical and computational demonstration of a stable trapping method based on monopole field superpositions for polar particles.

Findings

The trap is proven stable through stability analysis and molecular dynamics simulations.

It works for particles with zero orbital angular momentum.

The mechanism is illustrated with barium titanate rods.

Abstract

It is shown that a superposition of static and rapidly oscillating electric {\it monopole} (source) fields is capable of trapping particles with a permanent electric dipole moment. Thus, the new trapping mechanism differs fundamentally from saddle-point traps that use static and oscillating higher-multipole fields. An analytical stability analysis together with detailed molecular dynamics trajectory calculations prove that the trap is stable. Thin rods of barium titanate (BaTiO$_3$) provide an illustrative example for the working principle of the new trap. The effects of gravity are considered. The existence of a bifurcation regime is predicted. A particular strength of the new trap is that it also works for zero orbital angular momentum with respect to the field-generating electrodes.