Theoretical study on interactions between a collection of atoms and the electromagnetic field

We study squeezing in electromagnetic field quadrature components, produced by a collection of A two-level atoms interacting with a single mode of a strong electromagnetic field. We present analytic results both for short and long interaction times. At short times, squeezing grows with the number of atoms for a given initial number of photons. The maximum squeezing which can be achieved in a strong-field case is 66%. At long interaction times, collective effects increase the quadrature fluctuations, compared to the single-atom case. However, for a given number of atoms A, any initial pure atomic state exhibits squeezing when the mean photon number of the initial coherent field satisfies the condition n-bar>(2A ${)}^{4}$ . At times close to the first revival, strong squeezing can be achieved for special initial atomic conditions.We study squeezing in electromagnetic field quadrature components, produced by a collection of A two-level atoms interacting with a single mode of a strong electromagnetic field. We present analytic results both for short and long interaction times. At short times, squeezing grows with the number of atoms for a given initial number of photons. The maximum squeezing which can be achieved in a strong-field case is 66%. At long interaction times, collective effects increase the quadrature fluctuations, compared to the single-atom case. However, for a given number of atoms A, any initial pure atomic state exhibits squeezing when the mean photon number of the initial coherent field satisfies the condition n-bar>(2A${)}^{4}$ . At times close to the first revival, strong squeezing can be achieved for special initial atomic conditions.

Physical Review AMar 1, 199722 citations

Interaction of Atoms with an electromagnetic field

Igor I Sobel'man

Elsevier eBooksJan 1, 19720 citations

Electromagnetic Interaction of Atoms

The MIT Press eBooksAug 28, 20000 citations

Off-resonant transitions in the collective dynamics of multi-level atomic ensembles

Y. Miroshnychenko, Klaus Mølmer

We study the contributions of off-resonant transitions to the dynamics of a system of N multi-level atoms sharing one excitation and interacting with the quantized vector electromagnetic field. The rotating wave approximation significantly simplifies the derivation of the equations of motion describing the collective atomic dynamics, but it leads to an incorrect expression for the dispersive part of the atom–atom interaction terms. For the case of two-level atoms and a scalar electromagnetic field, it turns out that the atom–atom interaction can be recovered correctly if integrals over the photon mode frequencies are extended to incorporate negative values. We explicitly derive the atom–atom interaction for multi-level atoms, coupled to the full vector electromagnetic field, and we recover also in this general case the validity of the results obtained by the extension to negative frequencies of the formulas derived with the rotating wave approximation.We study the contributions of off-resonant transitions to the dynamics of a system of N multi-level atoms sharing one excitation and interacting with the quantized vector electromagnetic field. The rotating wave approximation significantly simplifies the derivation of the equations of motion describing the collective atomic dynamics, but it leads to an incorrect expression for the dispersive part of the atom–atom interaction terms. For the case of two-level atoms and a scalar electromagnetic field, it turns out that the atom–atom interaction can be recovered correctly if integrals over the photon mode frequencies are extended to incorporate negative values. We explicitly derive the atom–atom interaction for multi-level atoms, coupled to the full vector electromagnetic field, and we recover also in this general case the validity of the results obtained by the extension to negative frequencies of the formulas derived with the rotating wave approximation.

arXiv:1302.3036Journal of Physics B Atomic Molecular and Optical PhysicsNov 7, 20134 citations

Effects of the Stark Interaction in the Dynamics of an Atomic System in a Broadband Squeezed Electromagnetic Field

Andrew I. Trubilko, Ashat M. Basharov

The effects of the Stark interaction in the collective radiation of an ensemble of atoms in the field of a broadband electromagnetic field in a squeezed quantum state have been considered. It has been shown that the inclusion of the conditions for the formation of the squeezed field allows one to describe the dynamics of atoms in terms of random quantum creating, annihilating, and counting processes. The latter process is the Stark interaction of atoms and the field and manifests itself in the form of a trigger superradiance pulse generated by an ensemble of identical atoms excited by a quantized resonant squeezed electromagnetic field. The description is based on the kinetic equation derived for an open localized quantum system in a broadband squeezed quantized electromagnetic field. The resulting equation differs from the known ones, but agrees with them in particular and limiting cases.The effects of the Stark interaction in the collective radiation of an ensemble of atoms in the field of a broadband electromagnetic field in a squeezed quantum state have been considered. It has been shown that the inclusion of the conditions for the formation of the squeezed field allows one to describe the dynamics of atoms in terms of random quantum creating, annihilating, and counting processes. The latter process is the Stark interaction of atoms and the field and manifests itself in the form of a trigger superradiance pulse generated by an ensemble of identical atoms excited by a quantized resonant squeezed electromagnetic field. The description is based on the kinetic equation derived for an open localized quantum system in a broadband squeezed quantized electromagnetic field. The resulting equation differs from the known ones, but agrees with them in particular and limiting cases.

Journal of Experimental and Theoretical Physics LettersJul 1, 20255 citations

Atoms in Electromagnetic Fields

Günter Ludyk

Springer eBooksOct 25, 20170 citations

{)}^{4}

. At times close to the first revival, strong squeezing can be achieved for special initial atomic conditions.