Dynamical Casimir effects with atoms and spinning nanoparticles

Abstract

Motivated by recent experiments with levitated, ultra-fast rotating nanoparticles, this thesis presents new effects in the interaction of spinning particles with the quantum vacuum. The first part of the thesis studies the quantum electrodynamical analog of the Sagnac effect, in which the rotation of a neutral particle in the vicinity of an atom interferometer induces a phase on the propagating matter waves. The resulting phase is a geometric Berry phase proportional to the angular velocity of the particle. A rotation confined to a region of space leaving a trace of non-inertiality in an inertial frame suggests an analogy with the Aharonov-Bohm effect. Taking the particle’s plasmon resonances account, the analysis reveals that the phase magnitude is close to the limit of measurement for current state of the art atom interferometers. The force on an atom by a rotating particle is also calculated, and is shown to be analogous to the Coriolis force. The second part of the thesis deals with the photon emission by a rotating non-spherical neutral particle. Provided that the rotation axis is orthogonal to particle symmetry axis, the interaction of the particle with the field produces frequency sidebands of the scattered field, leading to the emission of dynamical Casimir photon pairs. The photon emission rate is obtained for metallic and dielectric spheroids and is enhanced when the rotation frequency is near a plasmonic or polaritonic resonance. In order to optimize the emission rate, the velocity of the particle’s tip is fixed and the dependence with the particle’s geometry is considered.