Turkish Journal of Physics 23, 887 (1999)
Arkadiusz ORŁOWSKI and Marian RUSEK
An effective approach to multiple scattering of electromagnetic waves by disordered dielectric media is developed. A self-consistent energy-conserving coupled-dipole model is used. Applications to the Anderson localization of electromagnetic waves are presented. A complete set of Maxwell's equations is used to describe the propagation of waves and the vector character of the electromagnetic field is fully taken into account.
Apr 5, 1999
Collective diffusion on hexagonal lattices - repulsive interactions
Surf. Sc. 441, 320 (1999)
ZAŁUSKA-KOTUR M. A. ; KRUKOWSKI S. ; TURSKI Ł. A.
Diffusion of interacting particle on a hexagonal lattice is studied by use of Monte Carlo simulations for a range of densities and temperatures including ordered and disordered phases. The decay of the initially prepared density perturbation is analyzed. Fast, local ordering happens at the beginning of system relaxation and clearly separates as a function of time the much slower global diffusion process. Locally equilibrated density perturbation decays according to the macroscopic diffusion equation, which allows a collective diffusion coefficient to be calculated. The density dependence of the collective diffusion coefficient is shown for several temperatures above and below the critical temperature.
ZAŁUSKA-KOTUR M. A. ; KRUKOWSKI S. ; TURSKI Ł. A.
Diffusion of interacting particle on a hexagonal lattice is studied by use of Monte Carlo simulations for a range of densities and temperatures including ordered and disordered phases. The decay of the initially prepared density perturbation is analyzed. Fast, local ordering happens at the beginning of system relaxation and clearly separates as a function of time the much slower global diffusion process. Locally equilibrated density perturbation decays according to the macroscopic diffusion equation, which allows a collective diffusion coefficient to be calculated. The density dependence of the collective diffusion coefficient is shown for several temperatures above and below the critical temperature.
Mar 5, 1999
New effects in light scattering from cold atoms trapped by harmonic potentials
A. Orlowski, M. Gajda, P. Krekora, R. J. Glauber, and J. Mostowski
First, we study the scattering of light by a single ultracold, trapped atom initially in the ground state of the trapping harmonic potential. We find interesting features of the scattering in the regime where the atomic recoil energy is much larger than the separation between oscillatory trap levels. Although we present the quan-tum mechanical expression for the scattering cross section, special attention is paid to the semiclassical analysis of the process. We show that the major characteristics of the scattering might be deduced from two conservation laws: conservation of energy and momentum in absorption and emission of photon process separately. These conservation laws impose a strong correlation between scattered-light characteristics and the position of the trapped atom at the moment of photon emission. A detailed analysis of the far-off resonance scattering of light from a single atom trapped in an isotropic harmonic potential is also given. In this case, we are able to assume a more realistic, i.e., thermal, initial state of the atomic center of mass. An exact closed-form expression for the differential scattering cross section is derived from a general S-matrix theory of scattering. The possibility of measuring the density–density correlation functions in light-scattering experiments is discussed.
Opt. Spectrosc. 87, 645 (1999)
First, we study the scattering of light by a single ultracold, trapped atom initially in the ground state of the trapping harmonic potential. We find interesting features of the scattering in the regime where the atomic recoil energy is much larger than the separation between oscillatory trap levels. Although we present the quan-tum mechanical expression for the scattering cross section, special attention is paid to the semiclassical analysis of the process. We show that the major characteristics of the scattering might be deduced from two conservation laws: conservation of energy and momentum in absorption and emission of photon process separately. These conservation laws impose a strong correlation between scattered-light characteristics and the position of the trapped atom at the moment of photon emission. A detailed analysis of the far-off resonance scattering of light from a single atom trapped in an isotropic harmonic potential is also given. In this case, we are able to assume a more realistic, i.e., thermal, initial state of the atomic center of mass. An exact closed-form expression for the differential scattering cross section is derived from a general S-matrix theory of scattering. The possibility of measuring the density–density correlation functions in light-scattering experiments is discussed.
Opt. Spectrosc. 87, 645 (1999)
Interference without interference: Directional properties of spontaneous emission
A. Orlowski and W. Zakowicz
A fully quantum-mechanical description of the spontaneous emission from an excited two-level atom placed in front of the two slit interferometer is given. Global modes of the electromagnetic field in a two slit system are derived within the Kirchhoff-Huygens diffraction approximation, serving as a base for the field quantization. The standard Fermi’s golden rule, supplemented by a factor coming from the nontrivial mode structure caused by the presence of the two slit interferometer, is used to show that interference results from the position dependent coupling between the atom and different field modes of the system.
Opt. Spectrosc. 87, 500 (1999)
A fully quantum-mechanical description of the spontaneous emission from an excited two-level atom placed in front of the two slit interferometer is given. Global modes of the electromagnetic field in a two slit system are derived within the Kirchhoff-Huygens diffraction approximation, serving as a base for the field quantization. The standard Fermi’s golden rule, supplemented by a factor coming from the nontrivial mode structure caused by the presence of the two slit interferometer, is used to show that interference results from the position dependent coupling between the atom and different field modes of the system.
Opt. Spectrosc. 87, 500 (1999)
Aug 21, 1998
Anderson localization of electromagnetic waves in confined dielectric media
Phys. Rev. E 59, 3655 (1999)
Marian Rusek and Arkadiusz Orłowski
Anderson localization of electromagnetic waves in random arrays of dielectric cylinders confined within a planar metallic waveguide is studied. The disordered dielectric medium is modeled by a system of randomly distributed two-dimensional electric dipoles. An effective theoretical approach based on the method of images is developed. A clear distinction between isolated localized waves (which exist already in finite media) and the band of localized waves (which appears only in the limit of the infinite medium) is presented. The Anderson localization emerging in the limit of an infinite medium is observed both in finite-size scaling analysis of transmission and in the properties of the spectra of some random matrices.
Marian Rusek and Arkadiusz Orłowski
Anderson localization of electromagnetic waves in random arrays of dielectric cylinders confined within a planar metallic waveguide is studied. The disordered dielectric medium is modeled by a system of randomly distributed two-dimensional electric dipoles. An effective theoretical approach based on the method of images is developed. A clear distinction between isolated localized waves (which exist already in finite media) and the band of localized waves (which appears only in the limit of the infinite medium) is presented. The Anderson localization emerging in the limit of an infinite medium is observed both in finite-size scaling analysis of transmission and in the properties of the spectra of some random matrices.
May 29, 1998
Wehrl's entropy and classification of states
Rep. Math. Phys. 43, 283 (1999)
A. Orłowski
The usefulness of Wehrl's entropy in quantum optics is investigated. Possible applications to the classification of quantum states with respect to their statistical properties are presented. A general variational proof of the observation that for a given average photon number the maximum Wehrl's entropy is attained for thermal states is given.
A. Orłowski
The usefulness of Wehrl's entropy in quantum optics is investigated. Possible applications to the classification of quantum states with respect to their statistical properties are presented. A general variational proof of the observation that for a given average photon number the maximum Wehrl's entropy is attained for thermal states is given.
Mar 18, 1998
Changes of the electrokinetic effects induced by guided light in capillary electrophoresis
Electrophoresis 20, 2493-2500 (1999)
Leonardo De Boni, Lilian T. C. França, Hans-Peter H. Grieneisen, Maciej Janowicz, Tarso B. L. Kist, Angelica R. Consiglio, Júlio R. Schoffen, Valter Stefani, Carlos Termignoni
The phenomenon of electrophoresis in free solution has been studied theoretically down to the molecular level for decades. In addition, intermolecular photo-induced proton transfer reactions, which occur in a wide class of molecules (phenols and aminoarenes) as well as proteins (green fluorescent protein), were also studied extensively. However, the study of the effect of light-induced electrophoretic mobility changes of the analytes in electrophoresis was begun only recently. In the present work, capillary zone electrophoresis was chosen as the environment to measure the magnitude of these electrophoretic mobility shifts induced by light. Background electrolytes (running electrolytes) with high refractive indices were developed, allowing the capillary to work like an optical fiber. The experimental conditions for obtaining stable coupling and guided laser light along the liquid core are discussed. Experimental evidence of band compression is observed, leading to a solitary wave behavior of the analyte band (2-naphthol). These solitary waves result from competition between thermal diffusion (dispersion mechanism) and a nonlinear (band compression) effect due to the combined electrophoresis phenomenon and absorption of guided light by the molecules of the band (which are subjected to a reversible intermolecular proton transfer reaction as one of their decay routes). The possibilities of applying this effect to different methods and techniques are also discussed.
Leonardo De Boni, Lilian T. C. França, Hans-Peter H. Grieneisen, Maciej Janowicz, Tarso B. L. Kist, Angelica R. Consiglio, Júlio R. Schoffen, Valter Stefani, Carlos Termignoni
The phenomenon of electrophoresis in free solution has been studied theoretically down to the molecular level for decades. In addition, intermolecular photo-induced proton transfer reactions, which occur in a wide class of molecules (phenols and aminoarenes) as well as proteins (green fluorescent protein), were also studied extensively. However, the study of the effect of light-induced electrophoretic mobility changes of the analytes in electrophoresis was begun only recently. In the present work, capillary zone electrophoresis was chosen as the environment to measure the magnitude of these electrophoretic mobility shifts induced by light. Background electrolytes (running electrolytes) with high refractive indices were developed, allowing the capillary to work like an optical fiber. The experimental conditions for obtaining stable coupling and guided laser light along the liquid core are discussed. Experimental evidence of band compression is observed, leading to a solitary wave behavior of the analyte band (2-naphthol). These solitary waves result from competition between thermal diffusion (dispersion mechanism) and a nonlinear (band compression) effect due to the combined electrophoresis phenomenon and absorption of guided light by the molecules of the band (which are subjected to a reversible intermolecular proton transfer reaction as one of their decay routes). The possibilities of applying this effect to different methods and techniques are also discussed.
Dec 19, 1997
Suppression of the Rabi oscillations in a cavity partially filled with a dielectric having a time-dependent refractive index
In this paper the dynamics of wave fields in a cavity, part of which is filled with a dielectric, are investigated. The wave equation is solved approximately using the method of multiple time scales. Phase modulations of the cavity modes in an adiabatic case are given up to the first order. A simple effective field Hamiltonian operator is derived and then used to analyze the interaction of radiation with a two-level atom passing through the cavity. Corrections to the Rabi oscillations due to the time-dependent frequency of the cavity photons are investigated. It is shown that adiabatic time dependence of the refractive index of the dielectric can lead to suppression of the Rabi oscillations of atomic inversion.
Physical Review A 57, 5016 (1998)
Physical Review A 57, 5016 (1998)
Jun 16, 1997
Radiative decay of Trojan wave packets
Zofia Bialynicka-Birula and Iwo Bialynicki-Birula
We calculate the decay rates due to spontaneous emission for electronic states described by Trojan wave packets. The spontaneous decay rate for a typical Trojan state (n=60) is six orders of magnitude smaller than the ionization rate and it is about one order of magnitude smaller than the rate for the corresponding ordinary circular Rydberg state.
Phys. Rev. A 56, 3623 (1997)
We calculate the decay rates due to spontaneous emission for electronic states described by Trojan wave packets. The spontaneous decay rate for a typical Trojan state (n=60) is six orders of magnitude smaller than the ionization rate and it is about one order of magnitude smaller than the rate for the corresponding ordinary circular Rydberg state.
Phys. Rev. A 56, 3623 (1997)
Feb 6, 1997
Band of localized electromagnetic waves in random arrays of dielectric cylinders
Marian Rusek, Arkadiusz Orłowski, and Jan Mostowski
Anderson localization of electromagnetic waves in random arrays of dielectric cylinders is studied. An effective theoretical approach based on analysis of probability distributions, not averages, is developed. The disordered dielectric medium is modeled by a system of randomly distributed two-dimensional electric dipoles. Spectra of certain random matrices are investigated and the appearance of the band of localized waves emerging in the limit of an infinite medium is discovered. It suggests deeper insight into the existing experimental results.
Phys. Rev. E 56, 4892 (1997)
Anderson localization of electromagnetic waves in random arrays of dielectric cylinders is studied. An effective theoretical approach based on analysis of probability distributions, not averages, is developed. The disordered dielectric medium is modeled by a system of randomly distributed two-dimensional electric dipoles. Spectra of certain random matrices are investigated and the appearance of the band of localized waves emerging in the limit of an infinite medium is discovered. It suggests deeper insight into the existing experimental results.
Phys. Rev. E 56, 4892 (1997)
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