scholarly journals MAGNETIC PHASE DIAGRAMS OF THE GENERALIZED SPIN-ONE-HALF FALICOV–KIMBALL MODEL

2007 ◽  
Vol 21 (08) ◽  
pp. 467-474 ◽  
Author(s):  
MARTIN ŽONDA

A combination of small-cluster exact-diagonalization calculations and a well-controlled approximative method is used to examine the ground-state phase diagrams of the spin-one-half Falicov–Kimball model extended by the spin-dependent on-site interaction (J) between localized spins and itinerant (d) electrons, as well as by external magnetic field (h). Both the magnetic ordering and metamagnetic transitions are analyzed as functions of h and the number of itinerant electrons (Nd) at selected J. Various magnetic superstructures including axial and diagonal spin stripes are observed for non-zero values of J and h. Moreover, it is shown that increasing h strongly stabilizes the fully and partially polarized states, while the non-polarized state is reduced.

2007 ◽  
Vol 21 (31) ◽  
pp. 5265-5274 ◽  
Author(s):  
AHMET ERDİNÇ

The ground-state phase diagrams are obtained for the spin-2 Ising model Hamiltonian with bilinear and biquadratic exchange interactions and a single-ion crystal field. The interactions are assumed to be only between nearest-neighbors. Obtained phase diagrams are presented in the (Δ,J), (K,J), (Δ/J,K/J), (Δ/|J|,K/|J|), (Δ/|K|,J/|K|), (H/J,Δ/J), (H/|J|,Δ/|J|), (H/J,K/J), and (H/|J|,K/|J|) planes where J, K, Δ, and H are the bilinear, biquadratic exchange interactions, the single-ion crystal field, and the external magnetic field, respectively. The influence of the external magnetic field on the spin configurations is investigated.


2013 ◽  
Vol 87 (13) ◽  
Author(s):  
Roman Verba ◽  
Vasil Tiberkevich ◽  
Konstantin Guslienko ◽  
Gennadiy Melkov ◽  
Andrei Slavin

2008 ◽  
Vol 22 (12) ◽  
pp. 1923-1932
Author(s):  
JIA LIU ◽  
ZI-YU CHEN

The influence of a perpendicular magnetic field on a bound polaron near the interface of a polar–polar semiconductor with Rashba effect has been investigated. The material is based on a GaAs / Al x Ga 1-x As heterojunction and the Al concentration varying from 0.2 ≤ x ≤ 0.4 is the critical value below which the Al x Ga 1-x As is a direct band gap semiconductor.The external magnetic field strongly altered the ground state binding energy of the polaron and the Rashba spin–orbit (SO) interaction originating from the inversion asymmetry in the heterostructure splitting of the ground state binding energy of the bound polaron. How the ground state binding energy will be with the change of the external magnetic field, the location of a single impurity and the electron area density have been shown in this paper, taking into account the SO coupling. The contribution of the phonons are also considered. It is found that the spin-splitting states of the bound polaron are more stable, and, in the condition of weak magnetic field, the Zeeman effect can be neglected.


1991 ◽  
Vol 06 (30) ◽  
pp. 2819-2826 ◽  
Author(s):  
GERALD V. DUNNE ◽  
ALBERTO LERDA ◽  
CARLO A. TRUGENBERGER

We construct exact many-body eigenstates of both energy and angular momentum for the N-anyon problem in an external magnetic field. We show that such states span the full ground state eigenspace and arise as correlation functions of Fubini-Veneziano vertex operators of string theory.


1992 ◽  
Vol 07 (38) ◽  
pp. 3593-3600
Author(s):  
R. CHITRA

The properties of the ground state of N anyons in an external magnetic field and a harmonic oscillator potential are computed in the large-N limit using the Thomas-Fermi approximation. The number of level crossings in the ground state as a function of the harmonic frequency, the strength and the direction of the magnetic field and N are also studied.


1980 ◽  
Vol 72 (10) ◽  
pp. 5649-5655 ◽  
Author(s):  
A. K. Theophilou ◽  
S. Thanos

Sign in / Sign up

Export Citation Format

Share Document