Appearance of multistability in a neuron model with network feedback

Three-dimensional localization of atoms in the polychromatic optical superlattice

“…In this case, owing to the non-linear interference effect there can appear a so-called rectified gradient force (RcGF) [5][6][7], which has the order of magnitude of the gradient force F g in a monochromatic standing wave [8,9]: F g ∼ 2πhΔ s /λ, but oscillates in space with the period L greatly exceeding the light wavelength λ, L λ. Therefore, the bichromatic field is capable of inducing not only OL with a microscopic period ∼ λ but also an optical superlattice (OSL) with a macroscopic period L: the arrays of superdeep potential wells [10] with the huge values of the depth W ∼hΔ s L/λ hΔs as compared to the monochromatic OL.…”

“…The steady-state Wigner function f (r, v) has been found containing full information on the state of the localized ensemble of the atoms. Unlike the traditional approach [5,6,[10][11][12][13][14] (where OSL is formed by the bichromatic field) the OSL formation has been studied in the polychromatic field: the superposition of the threecolour far-off-resonant field and partially coherent (fluctuating) field. We have shown that the action of such 3D polychromatic OSL at a certain field configuration is equivalent to the action of three 1D dissipative OSLs oriented along three mutually perpendicular axes.…”

“…Therefore, the bichromatic field is capable of inducing not only OL with a microscopic period ∼ λ but also an optical superlattice (OSL) with a macroscopic period L: the arrays of superdeep potential wells [10] with the huge values of the depth W ∼hΔ s L/λ hΔs as compared to the monochromatic OL. The work in [5][6][7]10] is based on the two-level model of an atom. Thereafter, in other papers (see [11][12][13] E-mail address: krasn@icm.krasn.ru.…”

Kinetics and Optical Properties of the Strongly Driven Gas Medium of Interacting Atoms

“…The impact approximation based on the appropriate formulation of the correlation functions (as in [14,16,17]) is alternative to the density matrix formalism. The careful introduction of binary collision integral describing intrinsic transitions in atoms during collisions for use in kinetic equations is the central moment in the impact theory (see [20,21]). In our macroscopic theory the items responsible for atomic transitions during short-range interactions (in comparison with the wavelength of a pumping field) are simplified in the relaxation approximation.…”

“…Experimental evidences of the influence of atom-atom interaction on spectral characteristics can be found in the earlier investigations (see, for example [11][12][13]). The theoretical description of the effects, including spectral narrowing and broadening, radiation trapping, caused by the long-range and short-range ("hard core" collisions) atomatom interactions starts its development approximately from the second half the twentieth century (see, for instance, [14][15][16][17][18][19][20][21]) reaching the modern state, for example, in [22][23][24]. In the current investigation we emphasize on the influence of the long-range interactions on the line shapes that was not theoretically explained earlier.…”