Magnetic resonance probing of ground state in the mixed valence correlated topological insulator SmB6
Introducing of topological insulator concept for fluctuating valence compound – samarium hexaboride
– has recently initiated a new round of studies aimed to clarify the nature of the ground state in this
extraordinary system with strong electron correlations. Here we discuss the data of magnetic resonance
in the pristine single crystals of SmB6 measured in 60 GHz cavity experiments at temperatures
1.8–300 K. The microwave study as well as the DC resistivity and Hall effect measurements
performed for the different states of SmB6  surface prove definitely the existence of the layer
with metallic conductivity increasing under lowering temperature below 5 K. Four lines with the
g-factors g ≈ 2 are found to contribute to the ESR-like absorption spectrum that may be attributed to
intrinsic paramagnetic centers on the sample’s surface, which are robust with respect to the surface
treatment. The temperature dependence of integrated intensity I(T) for main paramagnetic signal
is found to demonstrate anomalous critical behavior I(T) ~ (T* − T)ν with characteristic temperature
T* = 5.34 ± 0.05 K and exponent ν = 0.38 ± 0.03 indicating possible magnetic transition at the SmB6
 surface. Additional resonant magnetoabsorption line, which may be associated with either donorlike
defects or cyclotron resonance mode corresponding to the mass mc ~ 1.2m0, is reported.
The analysis of single-mode photon fluctuations and their counting statistics at the superradiant phase transition is presented. The study concerns the equilibrium Dicke model in a regime where the Rabi frequency, related to a coupling of the photon mode with a finite-number qubit environment, plays the role of the transition's control parameter. We use the effective Matsubara action formalism based on the representation of Pauli operators as bilinear forms with complex and Majorana fermions. Then, we address fluctuations of superradiant order parameter and quasiparticles. The average photon number, the fluctuational Ginzburg-Levanyuk region of the phase transition, and Fano factor are evaluated. We determine the cumulant-generating function which describes a full counting statistics of equilibrium photon number. Exact numerical simulation of the superradiant transition demonstrates quantitative agreement with analytical calculations.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.