Modern Physics Letters B

We propose an approach to statistical systems on lattices with sphere-like topology. Focusing on the Ising model, we consider the thermodynamic limit along a sequence of lattices with a finite number of defects approaching the large scale geometry of a tetrahedron. The hypothesis of scaling appears to hold at criticality, pointing at a sensible definition of the continuum limit of the model in the polyhedron. Finite size scaling is shown to produce, however, an anomalous exponent for the critical behavior of the correlation length, which we determine alternatively by looking at the temperature dependence of the gap at large lattice size.

We study a relativistic two-dimensional electron gas in the presence of a uniform external magnetic field and a random static scalar potential. We compute, in first order perturbation theory, the averages of the charge density and of the transverse conductivity for a white-noise potential, and show that, within this treatment, their quantized values are modified by the disorder.

Under quite plausible assumptions on double-layer quantum Hall states with strong interlayer correlation, we show in general framework that coherent tunneling of a single electron between two layers is possible. It yields Josephson effects with unit charge tunneling. The origin is that Halperin states in the quantum Hall states are highly degenerate in electron number difference between two layers in the absence of electrons tunneling.

In this paper the strain thermal Hall effect has been investigated in initial n-Si(P) and strongly compensated n-Si(Ni) samples of different compensation degree, which have been subject to uniform hydrostatic compression (UHC) under a pulse pressure regime ranging from 0 to 7×10⁸ Pa. An experimental investigation of the strain thermal effect in the n-Si(Ni) sample leads to an essential strain conductivity increase, which is largely controlled by density variations of majority carriers.

In the present study we report on the formation, characterization and magnetic susceptibility of two conventionally solidified quasicrystalline alloys with the nominal composition Al_67.5Cu_17.5Rh₁₅ (decagonal phase) and Al₇₀Cu₁₂Ru₁₈ (icosahedral phase). The characterization of the quasicrystalline state was examined by X-ray diffractometry (XRD), differential thermal analysis (DTA), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDXA). Magnetic susceptibility results in the temperature range from 5 to 300 K utilizing SQUID magnetometry under constant magnetic field H=1 kOe are presented.