Novel electrodynamic trapping mechanism for neutral, polar particles
Wesleyan University, Middletown, CT 06459-0155, USA
Received: 9 April 2011
Published online: 2 August 2011
A conceptually new trapping mechanism for neutral, polar particles is introduced and discussed. Unlike existing mechanisms that are based on oscillating saddle-point potentials or rotating electric dipole fields, the new mechanism is based on a superposition of ac and dc electric monopole fields that dynamically generate a minimum of the effective ponderomotive potential in which the particles are trapped. Extensive numerical simulations of the dynamics and the stability properties of trapped HC17N molecules and ferroelectric rods (made of barium titanate or croconic acid crystals) prove the validity of the new mechanism. The examples show that the same mechanism is applicable to the trapping of macroscopic as well as microscopic particles. The numerical results are backed by a physical pseudo-potential picture and an analytical stability analysis that provide physical insight into why and how the new mechanism works. A semi-quantum, Born-Oppenheimer-type calculation that treats the intrinsic rotational degree of freedom of HC17N quantum mechanically is also presented. A detailed discussion of engineering aspects shows that laboratory implementation of the new mechanism is within current technological reach.
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2011