Temperature dependence of the Mössbauer isomer shift

The isomer shift for nuclei in solids is calculated taking into account the core electron charge density, the overlap effects, the charge transfer effects, and the crystal field effects. The importance of the dynamical electron phonon interaction is pointed out. It is found that the phonon-induced dynamical configurational mixing and the dynamical charge transfer play an important role and contribute to a dynamical isomer shift which enhances the temperature-dependent second-order Doppler shift. It is found that the internal conversion and the electron capture give information which is related to the isomer shift. In mixedvalence compounds such as EuCu₂Si₂, the center shift of the M?ssbauer lines has been explained as if arising from the phonon-induced dynamical isomer shift.     

Net charge fluctuations at RHIC

We present measurements of dynamical net charge fluctuations in Au+Au collisions at $\sqrt {s_{NN} } = 20$ , 62, 130 and 200 GeV using the measure ν _+?,dyn. We observe the dynamical fluctuations are finite at all energies, and do not exhibit dependence on beam energy. We find net charge fluctuations violate the trivial 1/N scaling expected for nuclear collisions consisting of independent nucleon-nucleon interactions. We also find dynamical fluctuations exhibit sizable dependence of the pseudo-rapidity and azimuthal ranges of integration. We compare measured data with transport models and a toy model invoking radial flow, and show the bulk of the measured correlations can be accounted for by resonance production and radial collective flow.     

Wigner crystal in snaked nanochannels

We study the properties of a Wigner crystal in snaked nanochannels and show that they are characterized by a conducting sliding phase at low charge densities and an insulating pinned phase above a critical charge density. The transition between these phases has a devil’s staircase structure typical for the Aubry transition in dynamical maps and the Frenkel-Kontorova model. We discuss the implications of this phenomenon for charge density waves in quasi-one-dimensional organic conductors and for supercapacitors in nanopore materials.     

Charge distributions of many particle final states and the energy dependence of forward charge exchange

We will describe a possible dynamical origin of the energy dependence of charge exchange cross sections. Our main assumption is local compensation of charge in a certain class of many particle final states.     

Giant charge relaxation resistance in the Anderson model

We investigate the dynamical charge response of the Anderson model viewed as a quantum RC circuit. Applying a low-energy effective Fermi liquid theory, a generalized Korringa-Shiba formula is derived at zero temperature, and the charge relaxation resistance is expressed solely in terms of static susceptibilities which are accessible by Bethe ansatz. We identify a giant charge relaxation resistance at intermediate magnetic fields related to the destruction of the Kondo singlet. The scaling properties of this peak are computed analytically in the Kondo regime. We also show that the resistance peak fades away at the particle-hole symmetric point.     

Solitons of the modified KdV equation

We determine all reflectionless potentials for the one-dimensional charge symmetric Dirac operator, identify them as solitons of the modified KdV equation, and give the connection to the KdV solitons. An associated dynamical system is shown to be completely integrable.     

Event-by-event net charge fluctuations

We present analyses of event-by-event dynamical net charge fluctuations measured in 130 and 200 GeV Au+Au collisions with the STAR detector. The dynamical net charge fluctuations are evaluated using the ν _+-,dyn observable. Dynamical fluctuations measured in Au+Au collisions at 130 and 200 GeV are finite, and exceed charge conservation limits. They deviate from a perfect 1/N scaling and provide an indication that the collision dynamics varies with collision centrality.     

Investigation of transfer parameters in polymer films by the dynamical voltage-current characteristic method

We studied dynamical voltage-current characteristics of polymer dielectric films in a wide range of temperatures at various voltage ramp speeds. We carried out a theoretical analysis of such characteristics for the nondiffusive case in the presence of fixed charge. We used our methodology to calculate the mobility of mobile charges in the dielectric from the magnitude and position of peak current in the dynamical voltage-current characteristic.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 101–106, October, 1987.     

Hidden charge 2e Boson in doped Mott insulators

We construct the low-energy theory of a doped Mott insulator, such as the high-temperature superconductors, by explicitly integrating over the degrees of freedom far away from the chemical potential. For either hole or electron doping, a charge 2e bosonic field emerges at low energy. The charge 2e boson mediates dynamical spectral weight transfer across the Mott gap and creates a new charge e excitation by binding a hole. The result is a bifurcation of the electron dispersion below the chemical potential as observed recently in angle-resolved photoemission on Pb-doped Bi2Sr2CaCu2O8+delta (Pb2212).     

The role of electron correlations in the double ionization of helium by fast protons

We consider the double ionization (DI) of a helium atom by fast protons and study the role of electron correlations in this process. We develop a quantum-mechanical approach that takes into account the interaction of the emitted electrons in continuum and the dynamical charge screening of the ejected particles, which depends on their ejection kinematics. The interaction of the emitted electrons between themselves and with the core is described in the model of approximate 3C functions, while the dynamical charge screening is described by introducing effective charges of the emitted electrons and the ion core, which are determined by the particle momenta. The derived closed analytical expressions for the differential ionization cross sections have been applied to the case of a coplanar particle ejection geometry at various momenta q transferred to the atom. Analysis of our calculations has shown that the developed model describes adequately the available experimental data. Including the dynamical charge screening has a significant effect on the DI cross section and improves considerably the agreement between theory and experiment.     

Ionicity scale and piezoelectricity of crystals with zincblende- and wurtzite-type structure

We have tried to determine the ionicity of crystals with a dynamical effective ionic charge defined by the observed TO-LO splitting. We find excellent agreement between our results and the ionicity scale derived by Phillips from band gap theory. We confirm that the observed piezoelectric constants can be well accounted for on the basis of the Born lattice-dynamical treatment by adding the concept of charge transfer, and we have made an estimate of the latter.     

Quantization,coherent states and geometric phases of a generalized nonstationary mesoscopic RLC circuit

We present an alternative quantum treatment for a generalized mesoscopic RLC circuit with time-dependent resistance, inductance and capacitance. Taking advantage of the Lewis and Riesenfeld quantum invariant method and using quadratic invariants we obtain exact nonstationary Schrödinger states for this electromagnetic oscillation system. Afterwards, we construct coherent and squeezed states for the quantized RLC circuit and employ them to investigate some of the system’s quantum properties, such as quantum fluctuations of the charge and the magnetic flux and the corresponding uncertainty product. In addition, we derive the geometric, dynamical and Berry phases for this nonstationary mesoscopic circuit. Finally we evaluate the dynamical and Berry phases for three special circuits. Surprisingly, we find identical expressions for the dynamical phase and the same formulae for the Berry’s phase.     

Model description of surface charging during ultra-fast pulsed laser ablation of materials

We present a model describing the dynamical mechanisms responsible for generating fast ion ejection under ultra-short pulsed laser irradiation. The model is based on a simplified drift–diffusion approach describing the evolution of the laser-generated charge carriers, their transport, and the electric field generated as a result of quasi-neutrality breaking in the irradiated target. The importance of different processes in generating the non-thermal material-ejection mechanisms is discussed. A common frame is applied to dielectrics, semiconductors, and metals and different dynamical behaviour is observed. The modelling results are in good agreement with fs pump–probe studies and measurements of the velocity distributions of the emitted ions.     

Nonequilibrium charge susceptibility and dynamical conductance: identification of scattering processes in quantum transport

We calculate the nonequilibrium charge transport properties of nanoscale junctions in the steady state and extend the concept of charge susceptibility to the nonequilibrium conditions. We show that the nonequilibrium charge susceptibility is related to the nonlinear dynamical conductance. In spectroscopic terms, both contain the same features versus applied bias when charge fluctuation occurs in the corresponding electronic resonances. However, we show that, while the conductance exhibits features at biases corresponding to inelastic scattering with no charge fluctuations, the nonequilibrium charge susceptibility does not. We suggest that measuring both the nonequilibrium conductance and charge susceptibility in the same experiment will permit us to differentiate between different scattering processes in quantum transport.     

Spinodal decomposition of low-density asymmetric nuclear matter

We investigate the dynamical properties of asymmetric nuclear matter at low density. The occurrence of new instabilities, that lead the system to a dynamical fragment formation, is illustrated, discussing in particular the charge symmetry dependence of the structure of the most important unstable modes. We observe that instabilities are reduced by charge asymmetry, leading to larger size and time scales in the fragmentation process. Configurations with less asymmetric fragments surrounded by a more asymmetric gas are favoured. Interesting variances with respect to a pure thermodynamical prediction are revealed, that can be checked experimentally. All these features are deeply related to the structure of the symmetry term in the nuclear Equation of State (EOS) and could be used to extract information on the low density part of the EOS.     

Beam-energy and system-size dependence of dynamical net charge fluctuations

We present measurements of net charge fluctuations in Au + Au collisions at ?{s_NN }\sqrt {s_{NN} } = 19.6, 62.4, 130, and 200 GeV, Cu + Cu collisions at ?{s_NN }\sqrt {s_{NN} } = 62.4, 200 GeV, and p + p collisions at ?s\sqrt s = 200 GeV using the net charge dynamical fluctuations measure ν+ −,dyn. The dynamical fluctuations are non-zero at all energies and exhibit a rather modest dependence on beam energy. We find that at a given energy and collision system, net charge dynamical fluctuations violate 1/N _ch scaling, but display approximate 1/N _part scaling. We observe strong dependence of dynamical fluctuations on the azimuthal angular range and pseudorapidity widths.     

Chiral Symmetry Breaking for Fermions Charged under Large Lie Groups

We reexamine the dynamical generation of mass for fermions charged under various Lie groups with equal charge and mass at a high Grand Unification scale, extending the Renormalization Group Equations in the perturbative regime to two loops and matching to the Dyson-Schwinger Equations in the strong coupling regime.     

Continuous-time monitoring of Landau-Zener interference in a cooper-pair box

Landau-Zener (LZ) tunneling can occur with a certain probability when crossing energy levels of a quantum two-level system are swept across the minimum energy separation. Here we present experimental evidence of quantum interference effects in solid-state LZ tunneling. We used a Cooper-pair box qubit where the LZ tunneling occurs at the charge degeneracy. By employing a weak nondemolition monitoring, we observe interference between consecutive LZ-tunneling events; we find that the average level occupancies depend on the dynamical phase. The system's unusually strong linear response is explained by interband relaxation. Our interferometer can be used as a high-resolution Mach-Zehnder-type detector for phase and charge.     

The dynamical equation of the spinning electron

We obtain the relativistic and non-relativistic invariant dynamical equations of the spinning electron by means of invariance arguments. The dynamics expresses the evolution of the point charge which satisfies a fourthorder differential equation or, alternatively, by describing the evolution of both the center of mass and center of charge of the particle. These equations and the interaction between two electrons will be analyzed.     

Director configuration and dynamics of a nematic liquid crystal around a two-dimensional spherical particle: Numerical analysis using adaptive grids

We study numerically the director and orientational order parameter configurations in a nematic liquid crystal around a two-dimensional spherical particle on the basis of the tensor order parameter formalism. To properly account for the large length scale difference between the particle and the accompanying orientational defect, we devise an adaptive grid scheme in which the lattice spacing is automatically and locally adjusted in response to the spatial gradient of the orientational order parameter. This adaptive grid scheme is useful in studying dynamical as well as static orientational structures. We present a simulation result which shows how a hedgehog defect of topological charge -1 becomes unstable in two dimensions, and splits into a defect pair of topological charge -1/2, located symmetrically around the particle. Received 14 September 2000 and Received in final form 27 December 2000