Search results for "iTED"
showing 10 items of 2408 documents
Resonance Dipole-Dipole Interaction Between Two Accelerated Atoms in the Presence of a Reflecting Plane Boundary
2018
We study the resonant dipole-dipole interaction energy between two uniformly accelerated identical atoms, one excited and the other in the ground state, prepared in a correlated {\em Bell-type} state, and interacting with the scalar field or the electromagnetic field nearby a perfectly reflecting plate. We suppose the two atoms moving with the same uniform acceleration, parallel to the plane boundary, and that their separation is constant during the motion. We separate the contributions of vacuum fluctuations and radiation reaction field to the resonance energy shift of the two-atom system, and show that Unruh thermal fluctuations do not affect the resonance interaction, which is exclusivel…
Nonthermal effects of acceleration in the resonance interaction between two uniformly accelerated atoms
2016
We study the resonance interaction between two uniformly accelerated identical atoms, one excited and the other in the ground state, prepared in a correlated (symmetric or antisymmetric) state and interacting with the scalar field or the electromagnetic field in the vacuum state. In this case (resonance interaction), the interatomic interaction is a second-order effect in the atom-field coupling. We separate the contributions of vacuum fluctuations and radiation reaction to the resonance energy shift of the system, and show that only radiation reaction contributes, while Unruh thermal fluctuations do not affect the resonance interaction. We also find that beyond a characteristic length scal…
Enhanced resonant force between two entangled identical atoms in a photonic crystal
2013
We consider the resonant interaction energy and force between two identical atoms, one in an excited state and the other in the ground state, placed inside a photonic crystal. The atoms, having the same orientation of their dipole moment, are supposed prepared in their symmetrical state and interact with the quantum electromagnetic field. We consider two specific models of photonic crystals: a one-dimensional model and an isotropic model. We show that in both cases the resonant interatomic force can be strongly enhanced by the presence of the photonic crystal, as a consequence of the modified dispersion relation and density of states, in particular if the transition frequency of the atoms i…
Vacuum fluctuations and radiation reaction contributions to the resonance dipole-dipole interaction between two atoms near a reflecting boundary
2018
We investigate the resonance dipole-dipole interaction energy between two identical atoms, one in the ground state and the other in the excited state, interacting with the electromagnetic field in the presence of a perfectly reflecting plane boundary. The atoms are prepared in a correlated (symmetric or anti-symmetric) Bell-type state. Following a procedure due to Dalibard et. al. [J. Dalibard et. al., J. Phys. (Paris) {\bf 43}, 1617 (1982); {\bf 45}, 637 (1984)], we separate the contributions of vacuum fluctuations and radiation reaction (source) field to the resonance interaction energy between the two atoms, and show that only the source field contributes to the interatomic interaction, …
Effect of boundaries on vacuum field fluctuations and radiation-mediated interactions between atoms
2017
In this paper we discuss and review several aspects of the effect of boundary conditions and structured environments on dispersion and resonance interactions involving atoms or molecules, as well as on vacuum field fluctuations. We first consider the case of a perfect mirror, which is free to move around an equilibrium position and whose mechanical degrees of freedom are treated quantum mechanically. We investigate how the quantum fluctuations of the mirror's position affect vacuum field fluctuations for both a one-dimensional scalar and electromagnetic field, showing that the effect is particularly significant in the proximity of the moving mirror. This result can be also relevant for poss…
Tuning the collective decay of two entangled emitters by means of a nearby surface
2017
We consider the radiative properties of a system of two identical correlated atoms interacting with the electromagnetic field in its vacuum state in the presence of a generic dielectric environment. We suppose that the two emitters are prepared in a symmetric or antisymmetric superposition of one ground state and one excited state and we evaluate the transition rate to the collective ground state, showing distinctive cooperative radiative features. Using a macroscopic quantum electrodynamics approach to describe the electromagnetic field, we first obtain an analytical expression for the decay rate of the two entangled two-level atoms in terms of the Green's tensor of the generic external en…
Impact of electromagnetic fields and heat on spin transport signals in Y3Fe5O12
2019
Exploring new strategies to perform magnon logic is a key requirement for the further development of magnon-based spintronics. In this paper, we realize a three-terminal magnon transport device to study the possibility of manipulating magnonic spin information transfer in a magnetic insulator via localized magnetic fields and heat generation. The device comprises two parallel Pt wires as well as a Cu center wire that are deposited on the ferrimagnetic insulator ${\mathrm{Y}}_{3}{\mathrm{Fe}}_{5}{\mathrm{O}}_{12}$. While the Pt wires act as spin current injector and detector, the Cu wire is used to create local magnetostatic fields and additional heat, which impact both the magnetic configur…
Experimental investigations of two doubly excited NI multiplets
2005
Experimental Stark-broadening studies of two NI multiplets ( 1 D)3s 2 D - ( 1 D)3p 2 D° and ( 1 D)3s 2 D - ( 1 D) 3 p 2 F° are reported. Measurements were performed using a wall-stabilized arc operated at atmospheric pressure in helium with small amounts of nitrogen and hydrogen. The Stark broadening parameters: the electron impact width (w e ) and shift (d e ) have been determined.
A theoretical analysis of the intrinsic light-harvesting properties of xanthopterin
2014
Belonging to the family of pterins, which are common chromophores in several bio-organisms, xanthopterin has been shown experimentally (Plotkin et al., 2010) to have the ability of acting as a light-harvesting molecule. In the present study, multiconfigurational second-order perturbation theory is used to determine the stability of distinct amino/imino and lactam/lactim tautomers and the absorption and emission spectroscopic characteristics, electron donor and acceptor properties and the electron and charge transfer efficiencies via π-stacking. The lactam–lactam form 3H5H (and in a lesser extent 1H5H) is predicted to have the most appropriate intrinsic characteristics for the light-harvesti…
Impedance of space-charge-limited currents in organic light-emitting diodes with double injection and strong recombination
2006
The impedance model for a one-carrier space-charge-limited (SCL) current has been applied to explain some experimental features of double carrier organic light-emitting diodes. We report the analytical model of impedance of bipolar drift transport in SCL regime in the limit of infinite recombination. In this limit the ac impedance function is identical to that of a single carrier device, with a transit time modified by the sum of mobilities for electrons and holes, μn+μp. The static capacitance C(ω→0) is a factor of ¾ lower than the geometric capacitance, as observed for single carrier devices, but it is shifted to higher frequencies. It follows that impedance measurements in the dual-carri…