Search results for "Casimir-Polder force"
showing 10 items of 23 documents
A microscopic approach to Casimir forces between metal bodies
2014
We consider the Casimir interaction between macroscopic metallic objects in terms of the dispersion interactions (Casimir-Polder and van der Waals) between their constituents. Expressions for two- and three-body dispersion interactions between the microscopic parts of a metal are obtained, both in the retarded and non-retarded limits. They are then used to evaluate two- and three-body contributions of the Casimir force between two flat ideal metallic slabs. Our results show the non-applicability of the Hamaker approximation in this geometry. It is further seen that the three-body contributions give an overall repulsive contribution to the force, which is of the same order of magnitude as th…
Dynamical Casimir-Polder forces between an atom and a conducting wall
2008
Lamb shift of a uniformly accelerated hydrogen atom in the presence of a conducting plate
2009
We investigate the effects of acceleration on the energy-level shifts of a hydrogen atom interacting with the electromagnetic field and in the presence of an infinite perfectly conducting plate. We consider the contributions of vacuum fluctuations and of the radiation reaction field to the Lamb shift, and we discuss their dependence from the acceleration of the atom. We show that, because of the presence of the boundary, both vacuum field fluctuations and radiation reaction field contributions are affected by atomic acceleration. In particular, the effect of the vacuum field fluctuations on the energy-level shifts is not equivalent to that of a thermal field. We also discuss the dependence …
Dynamical Casimir-Polder forces
2011
We consider the dynamical Casimir-Polder force on an atom placed near an infinite conducting wall. The system is initially in a non equilibrium configuration such as a bare or a partially dressed state, and its time evolution is considered as well as the time dependence of the atom-wall Casimir-Polder interaction. A possible scheme to generate experimentally the initial partially dressed state and to detect the dynamical Casimir-Polder force is discussed.
Dynamical Casimir-Polder interaction between an atom and a real surface
2014
We discuss the dynamical (i.e. time-dependent) Casimir-Polder force between a neutral atom and a real surface of arbitrary material, under non-equilibrium conditions. More specifically, we consider a polarisable neutral atom placed near a surface with arbitrary dielectric properties and we investigate the dynamical dressing and the consequent dynamical Casimir-Polder potential after the non-adiabatic (sudden) change of parameters involved in the atom-field coupling, such as the atomic transition frequency or the transition dipole moment. Using time-dependent perturbation theory and the matter-assisted field approach, we discuss how the physical properties of the real surface can influence t…
Fluctuations of the Casimir-Polder force between an atom and a conducting wall
2007
We consider the quantum fluctuations of the Casimir-Polder force between a neutral atom and a perfectly conducting wall in the ground state of the system. In order to obtain the atom-wall force fluctuation we first define an operator directly associated to the force experienced by the atom considered as a polarizable body in an electromagnetic field, and we use a time-averaged force operator in order to avoid ultraviolet divergences appearing in the fluctuation of the force. This time-averaged force operator takes into account that any measurement involves a finite time. We also calculate the Casimir-Polder force fluctuation for an atom between two conducting walls. Experimental observabili…
Energy level shifts of a uniformly accelerated atom in the presence of boundary conditions
2009
We discuss the radiative level shifts of an atom moving with uniform acceleration near an infinite reflecting plate. We first consider the case of a two-level system interacting with a massless scalar field in the vacuum state. The acceleration of the two-level atom is supposed in a direction parallel to the conducting plate. We evaluate the contribution of vacuum fluctuations and of the radiation reaction field to the energy shift of the atomic levels, and discuss their behaviour as a function of the atomic acceleration and of the atom-plate distance. Then, we investigate the more general case of an hydrogen atom accelerating near a perfectly reflecting plate and interacting with the elect…
Field fluctuations near a conducting plate and Casimir-Polder forces in the presence of boundary conditions
2006
We consider vacuum fluctuations of the quantum electromagnetic field in the presence of an infinite and perfectly conducting plate. We evaluate how the change of vacuum fluctuations due to the plate modifies the Casimir-Polder potential between two atoms placed near the plate. We use two different methods to evaluate the Casimir-Polder potential in the presence of the plate. They also give new insights on the role of boundary conditions in the Casimir-Polder interatomic potential, as well as indications for possible generalizations to more complicated boundary conditions.
Casimir-Polder potentials as entanglement probe
2007
We have considered the interaction of a pair of spatially separated two-level atoms with the electromagnetic field in its vacuum state and we have analyzed the amount of entanglement induced between the two atoms by the non local field fluctuations. This has allowed us to characterize the quantum nature of the non local correlations of the electromagnetic field vacuum state as well as to link the induced quantum entanglement with Casimir-Polder potentials.
Dynamical Casimir-Polder force between an atom and a conducting wall
2008
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 the time-dependent atom-field interaction energy. Physical features and limits of validity of the results are discussed in detail.