On the beaches of the oceans may be found amongst many stones with irregular shapes also stones that are nearly perfect ellipsoids. In this work, two grinding processes in the surf for stones of ellipsoidal shape are described mathematically on the basis of simple physical models. The first...

The electron spin relaxation times by piezoelectric and polar optical phonon scattering in GaAs are calculated using the formula derived from the projection-reduction method. The temperature, magnetic field, and electron density dependences of the relaxation time are investigated. The electrons...

We consider gated graphene nanoribbons subject to Berry-Mondragon boundary conditions in the presence of weak impurities. Using field-theoretical methods, we calculate the density of charge carriers (and, thus, the quantum capacitance) as well as the optical and DC conductivities at zero...

We consider the resonant energy transfer from a two-dimensional Wannier exciton (donor) to a Frenkel exciton of a molecular crystal overlayer (acceptor) when the active media are separated by a metallic layer, possibly an electrode. We characterize the effect of the surface plasmon on this...

We propose a theory which deals with the structure and interactions of volume elements in liquid helium II. The approach consists of two nested models linked via parametric space. The short-wavelength part describes the interior structure of the fluid element using a non-perturbative approach...

The pseudopotential calculations have been performed to study the effect of carbon impurity on the electronic nature of hexagonal ultrathin boron nanotubes. The structural stability and electronic properties of C-substituted BNTs have been evaluated by first principles calculations. Three...

We investigate the effects of carbon (C) on hydrogen (H) solubility in copper (Cu) using a first-principles method. We show C can increase the solution energy of H in the bulk Cu originated from the charge density redistribution, which leads to a weak repulsion between H and C in Cu. On the...

We study the Mott transition in the half-filled Hubbard model with spatially alternating interactions by means of the coherent potential approximation. The phase boundary between metallic and insulating phases at zero temperature is derived and the nature of the Mott states is also considered....