Dynamical Casimir-Polder Force Research Articles

Dynamical atom-wall Casimir-Polder effect after a sudden change of the atomic position

We investigate the dynamical Casimir-Polder force between an atom and a conducting wall during the time evolution of the system from a partially dressed state. This state is obtained by a sudden change of the atomic position with respect to the plate. To evaluate the time-dependent atom-plate Casimir-Polder force we solve the Heisenberg equations for the field and atomic operators by an iterative technique. We find that the dynamical atom-plate Casimir-Polder interaction exhibits oscillation in time, and can be attractive or repulsive depending on time and the atom-wall distance. We also investigate the time dependence of global observables, such as the field and atomic Hamiltonians, and discuss some interesting features of the dynamical process bringing the interaction energy to the equilibrium configuration.

Dynamical Casimir–Polder force in a semi-infinite rectangle waveguide

In this paper, we study the dynamical Casimir–Polder force between an ensemble of identical two-level atoms and the wall of a rectangle waveguide with semi-infinite length. With the presence of both the rotating wave and counter rotating wave terms in the light–matter interaction Hamiltonian, we utilize the perturbation theory to solve the Heisenberg equation. Up to the seconder of coupling strength, we obtain the energy shift analytically and the Casimir–Polder force numerically. Our result shows that the dynamical behavior of the Casimir force is closely connected to the photon propagation in the waveguide. Therefore, we hope this work will stimulate the studies about the quantum effect in waveguide scenario.

Dynamical Casimir-Polder force between a two-level atom with different initial states and a dissipative cavity

In this paper, a model of interaction between a two-level atom and a dissipative cavity is considered. The dynamical Casimir–Polder forces between the atom and the cavity wall in different initial states are discussed and analyzed. The quasimode theory is used to describe the electromagnetic field. The results show that the magnitude and properties of the dynamical Casimir–Polder force are different in different initial states of atoms. By adjusting the initial state of the atom properly, the dynamical Casimir–Polder force can also reach zero. This conclusion has important reference significance for the application of quantum information.

Dynamical Casimir-Polder force between an excited atom and a conducting wall

We consider the dynamical atom-surface Casimir-Polder force in the non-equilibrium configuration of an atom near a perfectly conducting wall, initially prepared in an excited state with the field in its vacuum state. We evaluate the time-dependent Casimir-Polder force on the atom, and find that it shows an oscillatory behavior from attractive to repulsive both in time and in space. We also investigate the asymptotic behavior in time of the dynamical force and of related local field quantities, showing that the static value of the force, as obtained by a time-independent approach, is recovered for times much larger than the timescale of the atomic self-dressing, but smaller than the atomic decay time. We then discuss the evolution of global quantities such as atomic and field energies, and their asymptotic behavior. We also compare our results for the dynamical force on the excited atom with analogous results recently obtained for an initially bare ground-state atom. We show that new relevant features are obtained in the case of an initially excited atom, for example much larger values of the dynamical force with respect to the static one, allowing for an easier way to single-out and observe the dynamical Casimir-Polder effect.

Dynamical Casimir–Polder force on a partially dressed atom in a cavity comprising a dielectric

We put a two-level atom into a cavity comprising a dielectric with output coupling. An analytical expression of the dynamical Casimir–Polder force in such a system is obtained when the system starts from a partially dressed state. And the effects of several relevant parameters of the system on the time-dependent force are also discussed.

Dynamical Casimir-Polder Force Between a Metallic Particle and a Perfectly Conducting Plate

For the first time, we have studied the impact of magnetic polarizability of a neutral metallic particle on the dynamical Casimir-Polder force, when the particle is uniformly moving with relativistic velocity parallel to the surface of an ideally conducting plate. The material properties of particle are taken into account within the Drude model approach.

Dynamical Casimir–Polder force in a cavity comprising a dielectric with output coupling

Abstract A two-level atom is put into a cavity comprising a transparent dielectric with one-side output coupling. An analytical expression of the time-dependence Casimir–Polder force in such a system is obtained. Our results show that the force finally tends to a steady negative value after a short-time damped oscillation. The effects on the force of the relative dielectric constant and the cavity size are also discussed in detail, respectively.

The dynamical Casimir-Polder force in relativistic atomic motion near the surface of a thick plate

The dynamical Casimir-Polder force between a neutral atom (in the ground state) and a thick plate in relativistic motion of the atom in the direction parallel to the surface has been calculated. The material properties have been considered in the framework of the oscillator model of the atom and the Drude dielectric function for a plate. The limiting cases of the nonrelativistic velocity and perfectly conducting material of the plate have been discussed. A complex dependence of the force on the velocity (energy), the distance, and the material properties of the surface has been found.

Dynamical Casimir–Polder atom-surface interaction

We have calculated dynamical Casimir–Polder force between a moving ground state atom and a flat polarizable surface. The velocity of an atom can be close to the velocity of light. The material properties are taken into account using a single oscillator model of the atomic dynamic polarizability and the Drude dielectric function of a metal substrate. The limit cases of nonrelativistic velocities and an ideal metal substrate are also considered. We have found specific dependence of the calculated forces on the velocity (energy), distance and material properties.

Dynamical Casimir-Polder force on a partially dressed atom near a conducting wall

We study the time evolution of the Casimir-Polder force acting on a neutral atom in front of a perfectly conducting plate, when the system starts its unitary evolution from a partially dressed state. We solve the Heisenberg equations for both atomic and field quantum operators, exploiting a series expansion with respect to the electric charge and an iterative technique. After discussing the behavior of the time-dependent force on an initially partially dressed atom, we analyze a possible experimental scheme to prepare the partially dressed state and the observability of this new dynamical effect.

Dynamical Casimir-Polder force in a one-dimensional cavity with quasimodes

In this article, we consider the dynamic Casimir-Polder force between an atom and a conducting wall in a one-dimensional cavity. Using quasimode theory to describe the dissipation of the electromagnetic fields in the cavity, our investigation shows that the force oscillations are damped in a short time, and tend to a final, steady, negative value. We discuss in detail the effects on the force of the quasimode decay rate, the cavity size, and the atom-wall distance.

Dynamical Casimir-Polder force between an atom and a conducting wall

The time-dependent Casimir-Polder force arising during the time evolution of an initially bare two-level atom, interacting with the radiation field and placed near a perfectly conducting wall, is considered. Initially the electromagnetic field is supposed to be in the vacuum state and the atom in its ground state. The analytical expression of the force as a function of time and atom-wall distance is evaluated from the time-dependent atom-field interaction energy. Physical features and limits of validity of the results are discussed in detail.