Showing 1 - 10 of 65
The phase transitions of a ferromagnet spin-1/2 Ising superlattice consisting of two different materials are examined using the effective field theory. The critical temperature of the system is studied as a function of the thickness of the constituents in a unit cell, exchange interactions in...
Persistent link: https://www.econbiz.de/10010873441
The Hamiltonian of the magnetic superlattice with three-layer unit cell was treated within the Boson formalism. The Boson Green’s functions (BGFs) were derived and it was shown that the system for BGFs splits into two sets which lead to the energies with opposite signs, although the energies...
Persistent link: https://www.econbiz.de/10011061524
In this work, we compute the specific heat of a system of non-interacting fermions whose energy spectrum presents a self-similar character. The critical attractor of the logistic map is used to generate a multifractal energy spectrum. We study the temperature dependence of the specific heat for...
Persistent link: https://www.econbiz.de/10010872290
A theoretical study of the specific heat C(T) as a function of temperature in Fibonacci magnetic superlattices is presented. We consider quasiperiodic structures composed of ferromagnetic films, each described by the Heisenberg model, with biquadratic and bilinear coupling between them. We have...
Persistent link: https://www.econbiz.de/10010873644
In this paper we investigate the thermodynamical properties of electrons in one-dimensional quasiperiodic potentials, arranged in accordance with the pure and generalized Fibonacci sequences. The sequences are described in terms of a series of generations that obey peculiar recursion relations,...
Persistent link: https://www.econbiz.de/10011060154
We have performed a theoretical study of the specific heat C(T), as a function of temperature, of magnetic and semiconductor quasiperiodic structures. The quasiperiodic structures considered here are constructed according to the Fibonacci, double-period and Thue–Morse quasiperiodic sequences....
Persistent link: https://www.econbiz.de/10011061368
The purpose of this paper is to investigate the specific heat properties of electrons in one-dimensional quasiperiodic potentials, arranged in accordance with the generalized Fibonacci sequence. The electronic energy spectra are calculated using the one-dimensional Schrödinger equation in a...
Persistent link: https://www.econbiz.de/10011062603
The energy spectra of a variety of collective modes on quasiperiodic structures exhibit a complex fractal profile. Among the modes that have attracted particular attention in this context are the spin wave spectra of quasiperiodic magnetic multilayers that obey a substitutional sequence of the...
Persistent link: https://www.econbiz.de/10010589908
In this article we discuss some recent trends in the research of electron and phonon localization, specially in the field of quasiperiodic potentials. Then, a new scheme to detect and classify localization is developed by studying the band scaling of a related supercrystal made from replicas of...
Persistent link: https://www.econbiz.de/10010590696
We calculate the dynamical response of a group of non-interacting magnetic grains dispersed in a medium that imposes on them an uniaxial anisotropy. Numerical results are obtained for a collection of grains that has its volume distribution given by a Gaussian function centered in the average...
Persistent link: https://www.econbiz.de/10009282146