On Properties of the Isoscalar Giant Dipole Resonance

Main properties (strength function, energy-dependent transition density, branching ratios for direct nucleon decay) of the isoscalar giant dipole resonance in several medium-heavy mass spherical nuclei are described within a continuum-RPA approach, taking into account the smearing effect. All model parameters used in the calculations are taken from independent data. Calculation results are compared with available experimental data.Comment: 12 pages, 2 figure

Superconducting single-mode contact as a microwave-activated quantum interferometer

The dynamics of a superconducting quantum point contact biased at subgap voltages is shown to be strongly affected by a microwave electromagnetic field. Interference among a sequence of temporally localized, microwave-induced Landau-Zener transitions between current carrying Andreev levels results in energy absorption and in an increase of the subgap current by several orders of magnitude. The contact is an interferometer in the sense that the current is an oscillatory function of the inverse bias voltage. Possible applications to Andreev-level spectroscopy and microwave detection are discussed

Electromechanics of charge shuttling in dissipative nanostructures

We investigate the current-voltage (IV) characteristics of a model single-electron transistor where mechanical motion, subject to strong dissipation, of a small metallic grain is possible. The system is studied both by using Monte Carlo simulations and by using an analytical approach. We show that electromechanical coupling results in a highly nonlinear IV-curve. For voltages above the Coulomb blockade threshold, two distinct regimes of charge transfer occur: At low voltages the system behave as a static asymmetric double junction and tunneling is the dominating charge transfer mechanism. At higher voltages an abrupt transition to a new shuttle regime appears, where the grain performs an oscillatory motion back and forth between the leads. In this regime the current is mainly mediated by charges that are carried on the grain as it moves from one lead to the other.Comment: 8 pages, 10 figures, final version to be published in PR

High-temperature excess current and quantum suppression of electronic backscattering in a 1-D system

We consider the electronic current through a one-dimensional conductor in the ballistic transport regime and show that the quantum oscillations of a weakly pinned single scattering target results in a temperature- and bias-voltage independent excess current at large bias voltages. This is a genuine effect on transport that derives from an exponential reduction of electronic backscattering in the elastic channel due to quantum delocalization of the scatterer and from suppression of low-energy electron backscattering in the inelastic channels caused by the Pauli exclusion principle. We show that both the mass of the target and the frequency of its quantum vibrations can be measured by studying the differential conductance and the excess current. We apply our analysis to the particular case of a weakly pinned C60 molecule encapsulated by a single-wall carbon nanotube and find that the discussed phenomena are experimentally observable.Comment: 4 pages, 4 figure

Two-level Hamiltonian of a superconducting quantum point contact

In a superconducting quantum point contact, dynamics of the superconducting phase is coupled to the transitions between the subgap states. We compute this coupling and derive the two-level Hamiltonian of the contact.Comment: REVTeX, 5 pages, reference adde

Characters of (relatively) integrable modules over affine Lie superalgebras

In the paper we consider the problem of computation of characters of relatively integrable irreducible highest weight modules L over finite-dimensional basic Lie superalgebras and over affine Lie superalgebras g. The problem consists of two parts. First, it is the reduction of the problem to the [bar over g]-module F(L), where [bar over g] is the associated to L integral Lie superalgebra and F(L) is an integrable irreducible highest weight [bar over g]-module. Second, it is the computation of characters of integrable highest weight modules. There is a general conjecture concerning the first part, which we check in many cases. As for the second part, we prove in many cases the KW-character formula, provided that the KW-condition holds, including almost all finite-dimensional g-modules when g is basic, and all maximally atypical non-critical integrable g-modules when g is affine with non-zero dual Coxeter number.Simons Foundation. Postdoctoral Fellowshi

The Effect of a Frailty Management Program on the Rehabilitation of Elderly Patients after Surgical Treatment

The article performs the results of rehabilitation programs realized among senile patients after videolaparoscopic cholecystectomy, based on specific for geriatrics senile patients’ status assessment methods with determination of frailty and geriatric syndromes exten