Finite temperature magnon spectra in yttrium iron garnet from a mean field approach in a tight-binding model

A tight-binding model is formulated for the calculation of the electronic structure of a double strand of deoxyribonucleic acid (DNA). The theory is applied to DNA with a particular structure such as the ladder and decorated ladder structures. It is found that there is a novel type of metal–insulator transitions due to the hopping anisotropy of the system. A metal-semimetal-semiconductor transition is found in the former and an effective semiconductor-metal transition at finite temperature in the latter, as the effect of base paring between two strands of DNA is increased. The latter mechanism may be responsible for explaining the Meade and Kayyem's recent observation.

Download Full-text

Mean field theory study of a tight-binding model for the high Tc oxides

Solid State Communications ◽

10.1016/0038-1098(88)91043-5 ◽

1988 ◽

Vol 67 (4) ◽

pp. 349-353 ◽

Cited By ~ 4

Author(s):

X.Y. Chen ◽

W.P. Su ◽

C.S. Ting ◽

D.Y. Xing

Keyword(s):

Field Theory ◽

Mean Field Theory ◽

Tight Binding ◽

Mean Field ◽

Tight Binding Model ◽

Binding Model ◽

High Tc

Download Full-text

TRANSPORT IN A CLEAN GRAPHENE SHEET AT FINITE TEMPERATURE AND FREQUENCY

International Journal of Modern Physics B ◽

10.1142/s0217979208039794 ◽

2008 ◽

Vol 22 (16) ◽

pp. 2529-2536 ◽

Cited By ~ 33

Author(s):

N. M. R. PERES ◽

T. STAUBER

Keyword(s):

Graphene Sheet ◽

Finite Temperature ◽

Tight Binding ◽

Dc Conductivity ◽

Finite Conductivity ◽

Tight Binding Model ◽

Zero Temperature ◽

Electron Hole ◽

Binding Model ◽

Field Theoretical Model

We calculate the conductivity of a clean graphene sheet at finite temperatures starting from the tight-binding model. We obtain a finite value for the dc-conductivity at zero temperature. For finite temperature, the spontaneous electron-hole creation, responsible for the finite conductivity at zero temperature, is washed out and the dc-conductivity yields zero. Our results are in agreement with calculations based on the field-theoretical model for graphene.

Download Full-text

Spin-Polarization in Ultrathin Rh Layers on Fe (001)

MRS Proceedings ◽

10.1557/proc-313-595 ◽

1993 ◽

Vol 313 ◽

Author(s):

A. Chouairi ◽

H. Dreysse ◽

H. Nait-Laziz ◽

C. Demangeat

Keyword(s):

Spin Polarization ◽

Photoelectron Spectroscopy ◽

Tight Binding ◽

Mean Field ◽

Lattice Parameter ◽

Tight Binding Model ◽

Binding Model ◽

Fee Structure ◽

Self Consistent ◽

Good Agreement

ABSTRACTThe origin of the Rh polarization at the interface with Fe is discussed within a self-consistent mean-field parameterized tight-binding model. Since experimentally it is not yet known how Rh grows on Fe (001), in this paper we consider both fee and bec growth. When Rh grows in the fee structure, it expands its lattice parameter and a polarization is present up to 3 layers, whereas in the bec case only the Rh atoms at the interface are polarized. The results obtained are compared to recent spin- and angle-resolved photoelectron spectroscopy experiments. Good agreement with experiment is obtained in the case of a fee Rh configuration.

Download Full-text

Electronic structure and finite temperature magnetism of yttrium iron garnet

Electronic Structure ◽

10.1088/2516-1075/abd097 ◽

2020 ◽

Vol 2 (4) ◽

pp. 044002

Author(s):

Joseph Barker ◽

Dimitar Pashov ◽

Jerome Jackson

Keyword(s):

Electronic Structure ◽

Finite Temperature ◽

Yttrium Iron Garnet ◽

Yttrium Iron ◽

Iron Garnet

Download Full-text

Analysis and lattice imaging of a transitional event on garnets

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108490 ◽

1978 ◽

Vol 36 (1) ◽

pp. 270-271

Author(s):

J.Y. Laval

Keyword(s):

Yttrium Iron Garnet ◽

Reciprocal Lattice ◽

Transitional Zone ◽

Lattice Imaging ◽

Yttrium Iron ◽

X Ray ◽

Ionic Process ◽

The Matrix ◽

High Resolution Technique ◽

Iron Garnet

The exsolution of magnetite from a substituted Yttrium Iron Garnet, containing an iron excess may lead to a transitional event. This event is characterized hy the formation of a transitional zone at the center of which the magnetite nucleates (Fig.1). Since there is a contrast between the matrix and these zones and since selected area diffraction does not show any difference between those zones and the matrix in the reciprocal lattice, it is of interest to analyze the structure of the transitional zones.By using simultaneously different techniques in electron microscopy, (oscillating crystal method microdiffraction and X-ray microanalysis)one may resolve the ionic process corresponding to the transitional event and image this event subsequently by high resolution technique.

Download Full-text