Microwave radiation induced magneto-oscillations in the longitudinal and transverse resistance of a two-dimensional electron gas

We confirm the existence of magneto-resistance oscillations in a microwave-irradiated two-dimensional electron gas, first reported in a series of papers by Zudov et al. [Phys. Rev. B 64 (2001) 201311] and Mani et al. [Nature (London) 420 (2002) 646]. In our experiments, on a sample with a moderate mobility, the microwave induced oscillations are observed not only in the longitudinal but also in the transverse-resistance (Hall resistance). The phase of the oscillations is such that the decrease (increase) in the longitudinal resistance is accompanied by an increase (decrease) in the absolute value of the Hall resistance. We believe that these new results provide valuable new information to better understand the origin of this interesting phenomenon.     

Processes with Higgs Scalar Bosons in External Electromagnetic Fields

In this paper we consider the processes with real and virtual Higgs scalar H-boson in the presence of an external constant electromagnetic field. We get formulae for the probability of the H-boson emission by a charged lepton and the field radiative H-boson effects (i.e. the contribution to the mass and the anomalous magnetic moment of the lepton.     

Mass operator for a charged lepton in the Weinberg-Salam theory in a constant external field

An expression is found for the propagator of a charged W-boson in the presence of an arbitrary flat-wave electromagnetic field. The W-boson contribution to the mass operator of a charged lepton moving in a constant external electromagnetic field is computed in the second order of perturbation theory in the Weinberg-Salam model. A closed expression is obtained for the vacuum W-boson contribution (independent of the external field) to the anomalous magnetic moment of a charged lepton.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 55–57, December, 1985.     

LSO-Ce fluorescence spectra and kinetics for UV,VUV and X-ray excitation

Abstract

LSO-Ce fluorescence emission and excitation spectra and decay kinetics have been measured for UV, VUV and X-ray excitation at RT and 80 K. The features of the fluorescence excitation spectra of two types of cerium centres in the region 3 to 6 eV are analysed in the assumption of competitative absorption between them. It is shown that the centres can have similar absorption bands. Forbidden energy bandgap for LSO is evaluated to be not less than 6.5 eV.     

Energy losses of a neutron star due to inverse muon decay in the superstrong magnetic field

The emission of a pair of neutrinos by a charged lepton under the influence of a strong magnetic field is examined. The expression found in general form for the probability of the process l l'vV in the strong magnetic field of a neutron star is used to evaluate the contribution of inverse muon decaye vV to the energy losses of the neutron star. The conditions under which this contribution to the energy losses of a neutron star may compete with that due to neutrino pair emission in the processe evV are discussed.Lomonosov State University, Moscow. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 39–44, July, 1995.     

Emission properties of a Tm30.1mm+:GdVO4 microchip laser at 1.9 μm

4 as a host for thulium has several advantages for diode pumping in comparison with other crystals. The absorption cross section of thulium in GdVO₄ is considerably stronger and broader than in YAG and YLF and the spectrum is shifted closer to the emission wavelength of commercially available AlGaAs laser diodes. In our paper, we report on the temporal and spectral emission properties of a monolithical Tm^30.01mm+([%at.]6.9):GdVO₄ microchip laser at 1.9 μm. The laser can be adjusted to emit either cw or in an oscillating regime. Slope efficiencies up to 47% are achieved. This value exceeds the Stokes limit of 42%. Received: 31 March 1998/Revised version: 02 June 1998     

Detection of single-electron charging in an individual InAs quantum dot by noncontact atomic-force microscopy

Single-electron charging in an individual InAs quantum dot was observed by electrostatic force measurements with an atomic-force microscope (AFM). The resonant frequency shift and the dissipated energy of an oscillating AFM cantilever were measured as a function of the tip-back electrode voltage, and the resulting spectra show distinct jumps when the tip was positioned above the dot. The observed jumps in the frequency shift, with corresponding peaks in dissipation, are attributed to a single-electron tunneling between the dot and the back electrode governed by the Coulomb blockade effect, and are consistent with a model based on the free energy of the system. The observed phenomenon may be regarded as the "force version" of the Coulomb blockade effect.     

Asymmetry of neutrino emission from neutron beta decay in superdense matter and a strong magnetic field

The probability of neutron beta decay in the presence of degenerate magnetized matter consisting of electrons, protons, and neutrons is calculated by using exact solutions to the Dirac equation for charged particles in a uniform magnetic field. The asymmetry of the angular distribution of the momentum carried away by product antineutrinos is studied with allowance for the effect of a strong magnetic field. The values of basic parameters (magnetic-field strength, matter density, and matter temperature) that affect the reaction being considered are chosen in such a way as to render this investigation applicable to an analysis of the cooling of a neutron star.     

The effect of plasmon mass on spin light of neutrino in dense matter

We develop the theory of spin light of neutrino in matter (SLν) and include the effect of plasma influence on the emitted photon. We use the special technique based on exact solutions of particles wave equations in matter to perform all the relevant calculations, and track how the plasmon mass enters the process characteristics including the neutrino energy spectrum, SLν rate and power. The new feature it induces is the existence of the process threshold for which we have found the exact expression and the dependence of the rate and power on this threshold condition. The SLν   spatial distribution accounting for the above effects has been also obtained. These results might be of interest in connection with the recently reported hints of ultra-high energy neutrinos E=1÷10 PeV$E=1÷10\text{PeV}$ observed by IceCube.