The dynamics of an initially bare pair two-level atoms at distance R is investigated. coupled to the vacuum radiation field in multipolar scheme and dipole approximation. Heisenberg equations motion for various atomic operators are obtained neglecting terms O(${\mathit{e}}^{3}$) t smaller than spontaneous relaxation time. A rigorous proof causality atom-atom interaction given. Interatomic correlations, however, shown develop tR/c. This early development be compatible with principle...

We show that Casimir-Polder forces between two relativistic uniformly accelerated atoms exhibit a transition from the short distance thermal-like behavior predicted by Unruh effect to long nonthermal behavior, associated with breakdown of local inertial description system. This phenomenology extends thermal response detected single observer an spatially extended system particles, and we identify characteristic length scale for this crossover inverse proper acceleration atoms. Our results are...

The contribution of vacuum fluctuations and the radiation reaction to energy-level shifts a hydrogen atom, moving with uniform acceleration interacting electromagnetic field, is considered. It found that field not affected by acceleration, whereas fluctuations' depends on acceleration. differences previous results for an accelerated two-level atom scalar are discussed in detail; particular, it shown effect atomic level shifts, contrarily case, totally equivalent thermal field. argued this...

We study the resonance interaction between two uniformly accelerated identical atoms, one excited and other in ground state, prepared a correlated (symmetric or antisymmetric) state interacting with scalar field electromagnetic vacuum state. In this case (resonance interaction), interatomic is second-order effect atom-field coupling. separate contributions of fluctuations radiation reaction to energy shift system, show that only contributes, while Unruh thermal do not affect interaction....

We consider the Casimir-Polder interaction between two atoms, one in ground state and other its excited state. The is time-dependent for this system, because of dynamical self-dressing spontaneous decay atom. calculate potential atoms using an effective Hamiltonian approach. results obtained their physical meaning are discussed compared with previous based on a time-independent approach which uses non-normalizable dressed

A spinless, nonrelativistic hydrogen atom coupled to an electromagnetic field is considered. The interaction taken in the minimal-coupling form, and ground state of system obtained by straightforward perturbation theory. form cloud virtual photons surrounding studied through quantum-mechanical average on this appropriately defined coarse-grained energy-density (CGED) operator W(r\ensuremath{\rightarrow}). properties W(r\ensuremath{\rightarrow}) are order show that can give a reliable...

We consider a scalar field in one-dimensional cavity with mobile wall. The wall is assumed bounded by harmonic potential and its mechanical degrees of freedom are treated quantum mechanically. possible motion the makes length variable, yields wall-field interaction an effective among modes cavity. ground state coupled system calculate average number virtual excitations induced interaction, as well value energy density. compare our results analogous quantities for fixed walls, show correction...

We consider a two-level system such as atom, interacting with cavity field mode in the rotating wave approximation, when atomic transition frequency or is periodically driven time. show that both cases, for an appropriate choice of modulation parameters, state amplitudes generic $n${-}excitation subspace obey same equations motion can be obtained from \emph{static} non-Hermitian Jaynes-Cummings Hamiltonian ${\mathcal PT}$ symmetry, imaginary coupling constant. This gives further support to...

We investigate the resonance interaction energy between two uniformly accelerated identical atoms, interacting with scalar field or electromagnetic in vacuum state, reference frame coaccelerating atoms. assume that one atom is excited and other ground they are prepared their correlated symmetric antisymmetric state. Using perturbation theory, we separate, at second order atom-field coupling, contributions of fluctuations radiation reaction to shift system. show only term contributes while...

We consider the van der Waals force involving excited atoms in general environments, constituted by magnetodielectric bodies. develop a dynamical approach studying dynamics of and field, mutually coupled. When only one atom is excited, our theory suggests that for large distances acting on ground-state monotonic, while spatially oscillating. show how this latter can be related to known oscillating Casimir-Polder an near (ground-state) body. Our also reveals population-induced dynamics: times...

Dispersion interactions are long-range between neutral ground-state atoms or molecules, polarizable bodies in general, due to their common interaction with the quantum electromagnetic field. They arise from exchange of virtual photons atoms, and, case three more not additive. In this review, after having introduced relevant coupling schemes and effective Hamiltonians, as well properties vacuum fluctuations, we outline main dispersion interactions, both nonretarded (van der Waals) retarded...

A spinless hydrogen atom coupled to the electromagnetic field is considered within context of nonrelativistic quantum electrodynamics. The atom-field interaction taken in minimal-coupling form and Coulomb gauge used. When system its ground state fluctuates away from vacuum has virtual admixtures uncoupled lowest eigenstate. electric- magnetic-field-energy densities that arise fluctuations are determined as functions distance atom. relationship between these field-energy retarded long-range...

We analyze the magnetic dipole contribution to atom-surface dispersion forces. Unlike its electrical counterpart, it involves small transition frequencies that are comparable thermal energy scales. A significant temperature dependence is found near surfaces with a nonzero dc conductivity, leading strong suppression of force at $T>0$. use response theory for surface material and discuss both normal metals superconductors. The asymptotes free interaction entropy calculated analytically over...

We study the optomechanical coupling of a oscillating effective mirror with Rydberg atomic gas, mediated by dynamical atom-mirror Casimir-Polder force. This may produce near-field resonant excitation whose probability scales as ∝(d(2)an(4)t)(2)/z(0)(8), where z(0) is average atom-surface distance, d dipole moment, mirror's oscillation amplitude, n initial principal quantum number, and t time. propose an experimental configuration to realize this system cold atom gas trapped at distance ∼2×10...

We consider a system of two cavities separated by reflecting boundary finite mass that is free to move and bounded its equilibrium position harmonic potential. This yields an effective mirror-field interaction, as well interaction between the field modes mediated movable boundary. Two massless scalar fields are defined in each cavity. second-order interacting ground state system, contains virtual excitations both mirror's degrees freedom fields. investigate correlation functions observables...

We consider a multilevel atom such as an hydrogen atom, interacting with the quantum electromagnetic field, in dressed ground state of system. evaluate by perturbation theory system, within dipole approximation; we investigate and review effect self-dressing on several field atomic observables. Specifically, obtain general expressions renormalized electric magnetic fluctuations energy densities around analyze their scaling distance from obtaining approximated so-called near far zone. also...

We consider vacuum fluctuations of the quantum electromagnetic field in presence an infinite and perfectly conducting plate. evaluate how change due to plate modifies Casimir-Polder potential between two atoms placed near use different methods They also give new insights on role boundary conditions interatomic potential, as well indications for possible generalizations more complicated conditions.

We develop a dynamical approach to study the Casimir-Polder force between an initially bare molecule and magnetodielectric body at finite temperature, valid for arbitrary properties also in presence of chiral effects. Switching on interaction field particular time, we resulting temporal evolution interaction. The self-dressing its population-induced dynamics are accounted discussed. In particular, find that surface oscillates time with frequency related molecular transition frequency. verify...

The time-dependent electric-energy density surrounding a two-level atom fixed at r = 0 is studied, the being taken in its ground state t and field having initially only one photon delocalized mode. atom-field coupling includes both rotating counterrotating terms. energy wave approximation shown to behave noncausally, while presence of complete it be affected within sphere radius ct centred on atom. It concluded that terms are essential order ensure causality cannot neglected any accurate...

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

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

We consider the resonant interaction energy and force between two identical atoms, one in an excited state other ground state, placed inside a photonic crystal. The having same orientation of their dipole moment, are supposed prepared symmetrical interact with quantum electromagnetic field. specific models crystals: one-dimensional model isotropic model. show that both cases interatomic can be strongly enhanced by presence crystal, as consequence modified dispersion relation density states,...