Electronic Structure and Antiferromagnetism in La2CuO4

1987 ◽  
Vol 99 ◽  
Author(s):  
P. A. Sterne ◽  
C. S. Wang ◽  
G. M. Stocks ◽  
W. M. Temmerman
Keyword(s):  
Electronic Structure ◽  
Brillouin Zone ◽  
Antiferromagnetic Order ◽  
Stoichiometric Compound ◽  
Zone Boundary ◽  
Energy Bands ◽  
Brillouin Zone Boundary ◽  
Spin Polarized ◽  
Self Consistent ◽  
Boundary States

ABSTRACTSelf-consistent spin-polarized energy bands have been calculated for tetragonal and orthorhombic La2CuO4. No stable antiferromagnetic order is found in either the stoichiometric compound or oxygen deficient La2CuO3.75. Constraining the occupancy of Brillouin zone boundary states leads to a small antiferromagnetic moment in both systems which is rapidly quenched by Ba doping.

Angular control of acoustic waves oblique incidence by phononic crystals based on Dirac cones at the Brillouin zone boundary

2018 ◽  
Vol 382 (6) ◽  
pp. 423-427 ◽  
Author(s):  
Wen-Qiang Zhang ◽  
Xin Zhang ◽  
Fu-Gen Wu ◽  
Yuan-Wei Yao ◽  
Shui-Fang Lu ◽  
...  
Keyword(s):  
Brillouin Zone ◽  
Acoustic Waves ◽  
Oblique Incidence ◽  
Phononic Crystals ◽  
Zone Boundary ◽  
Brillouin Zone Boundary

Photonic Band Structure of Nanochannel Glass Materials

1996 ◽  
Vol 431 ◽  
Author(s):  
A. Rosenberg ◽  
R. J. Tonucci ◽  
H.-B. Lin
Keyword(s):  
Band Structure ◽  
Brillouin Zone ◽  
Near Infrared ◽  
Nearest Neighbor ◽  
Dielectric Structure ◽  
Zone Boundary ◽  
Photonic Band Structure ◽  
Brillouin Zone Boundary ◽  
Photonic Band ◽  
Good Agreement

AbstractWe demonstrate that nanochannel glass (NCG) materials are ideal for investigating twodimensional (2D) photonic band-structure effects. The NCG materials we have studied consist of triangular arrays of glass cylinders embedded in a glass matrix, having center-tocenter nearest-neighbor separations from 0.54 to 1.08 μm. The indices of refraction of the two glasses differ by less than 0.02 in the relevant spectral region. Narrow attenuation features occur whenever the dispersion relation for light propagating within such a periodic dielectric structure crosses a Brillouin zone boundary. The attenuations corresponding to the first Brillouin zone appear in the near-infrared (IR), at wavelengths between 1 and 3 μm, in good agreement with calculations.

ON THE ELECTRONIC STRUCTURE OF CrO2: NEW EXPERIMENTS AND THEORY

1993 ◽  
Vol 07 (01n03) ◽  
pp. 345-348 ◽  
Author(s):  
H. BRÄNDLE ◽  
D. WELLER ◽  
J. C. SCOTT ◽  
J. STICHT ◽  
P. M. OPPENEER ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Energy Range ◽  
Ab Initio ◽  
Optical Conductivity ◽  
Optical Constants ◽  
Conductivity Tensor ◽  
Experimental Confirmation ◽  
Spin Polarized ◽  
Self Consistent ◽  
First Time

Spectroscopic investigations of the optical constants n and k and the magneto-optical polar Kerr effects θK and εK were used to deterimine the diagonal and off-diagonal conductivity tensor elements of CrO 2 in the energy range 0.8-5eV. The data can be readily explained on the basis of self-consistent spin-polarized bandstructure calculations. A direct comparison of the measured and calculated diagonal optical conductivity is presented for the first time, which can be viewed as experimental confirmation of the ab initio calculated bandstructure of CrO 2.

Tilt and acoustic instabilities in ABX 4, A 2 BX 4 and ABX 3 perovskite structure types: their role in the incommensurate phases of the organic–inorganic perovskites

2005 ◽  
Vol 61 (6) ◽  
pp. 616-626 ◽  
Author(s):  
Ian Peter Swainson
Keyword(s):  
Brillouin Zone ◽  
Three Dimensional ◽  
Low Frequency ◽  
Zone Boundary ◽  
Brillouin Zone Boundary ◽  
Perovskite Layer ◽  
Modulated Phases ◽  
Acoustic Instabilities ◽  
Incommensurate Phases ◽  
Zero Frequency

An examination of the tilt modes and other low-frequency modes is made for an isolated, untilted perovskite layer, which maps very simply to the ABX 4 perovskites. A sheet of pure tilts exists at the Brillouin Zone boundary at {ξ, ½, ζ}. An instability is also found at all wavevectors which can be described as continuously varying from pure tilts to pure layer displacements as a function of the wavevector. Analysis is extended by considering the stacking of layers in the I-centered A 2 BX 4-layer perovskites. The effect of freezing in the commensurate tilt required to generate the Cmca tilt system, pertinent to the modulated phases of propylammonium salts, is examined. The zero-frequency modes are restricted to two planes in the Brillouin Zone. All of the observed wavevectors associated with modulated phases, and the commensurately tilted propylammonium tetrachlorocadmate, are consistent with this calculation. The effect of full three-dimensional connectivity is briefly reviewed for the true ABX 3 perovskites. While pure tilt incommensurates appear to be hypothetically possible, they do not appear to have been observed to date.

scholarly journals Nodal Brillouin-zone boundary from folding a Chern insulator

2017 ◽  
Vol 95 (5) ◽  
Author(s):  
Li-Jun Lang ◽  
Shao-Liang Zhang ◽  
Qi Zhou
Keyword(s):  
Brillouin Zone ◽  
Zone Boundary ◽  
Brillouin Zone Boundary

Magnetic excitations at the Brillouin zone boundary in Mn (17%Fe, 3%Cu) alloy

2004 ◽  
Vol 350 (1-3) ◽  
pp. E79-E81
Author(s):  
J Jankowska-Kisielińska ◽  
K Mikke ◽  
B Hennion
Keyword(s):  
Brillouin Zone ◽  
Zone Boundary ◽  
Brillouin Zone Boundary ◽  
Magnetic Excitations ◽  
Cu Alloy
Sign in / Sign up

Export Citation Format

Share Document