scholarly journals Spectral function of the electron in a superconducting resonating valence-band state

2002 ◽  
Vol 65 (21) ◽  
Author(s):  
V. N. Muthukumar ◽  
Z. Y. Weng ◽  
D. N. Sheng
Keyword(s):  
Spectral Function ◽  
Valence Band ◽  
Band State ◽  
Valence Band State

scholarly journals Electronic structure of biaxially strained wurtzite crystals GaN, AlN, and InN

1996 ◽  
Vol 1 ◽  
Author(s):  
J. A. Majewski ◽  
M. Städele ◽  
P. Vogl
Keyword(s):  
Electronic Structure ◽  
Total Energy ◽  
Valence Band ◽  
First Principles ◽  
Degrees Of Freedom ◽  
Local Density ◽  
Structural Parameters ◽  
Spin Orbit ◽  
Biaxial Strain ◽  
Valence Band State

We present first-principles studies of the effect of biaxial (0001)-strain on the electronic structure of wurtzite GaN, AlN, and InN. We provide accurate predictions for the valence band splittings as a function of strain which greatly facilitates the interpretation of data from samples with unintentional growth-induced strain. The present calculations are based on the total-energy pseudopotential method within the local-density formalism and include the spin-orbit interaction nonperturbatively. For a given biaxial strain, all structural parameters are determined by minimization of the total energy with respect to the electronic and ionic degrees of freedom. Our calculations predict that the valence band state Γ9(Γ6) lies energetically above the Γ7(Γ1) states in GaN and InN, in contrast to the situation in AlN. In all three nitrides, we find that the ordering of these two levels becomes reversed for some value of biaxial strain. In GaN, this crossing takes place already at 0.32% tensile strain. For larger tensile strains, the top of the valence band becomes well separated from the lower states. The computed crystal-field and spin-orbit splittings in unstrained materials as well as the computed deformation potentials agree well with the available experimental data.

Effects of Giant Optical Anisotropy in R-plane GaN/AlGaN Quantum Wells by Valence Band Mixing

PIERS Online ◽  
2006 ◽  
Vol 2 (6) ◽  
pp. 562-566 ◽  
Author(s):  
Chun-Nan Chen ◽  
Kao-Feng Yarn ◽  
Win Jet Luo ◽  
Jih-Chen Chiang ◽  
Ikai Lo ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Valence Band ◽  
Optical Anisotropy ◽  
Band Mixing ◽  
Valence Band Mixing

scholarly journals Erratum: Observation of monolayer valence band spin-orbit effect and induced quantum well states in MoX2

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Nasser Alidoust ◽  
Guang Bian ◽  
Su-Yang Xu ◽  
Raman Sankar ◽  
Madhab Neupane ◽  
...  
Keyword(s):  
Quantum Well ◽  
Valence Band ◽  
Spin Orbit ◽  
Quantum Well States

Oxidation of W(110): valence-band and W(4f) core-level spectroscopy

1994 ◽  
Vol 312 (1-2) ◽  
pp. 151-156 ◽  
Author(s):  
Charles H.F. Peden ◽  
Neal D. Shinn
Keyword(s):  
Valence Band ◽  
Core Level

scholarly journals Non-Debye Relaxations: Two Types of Memories and Their Stieltjes Character

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 477
Author(s):  
Katarzyna Górska ◽  
Andrzej Horzela
Keyword(s):  
Stochastic Processes ◽  
Spectral Function ◽  
Evolution Equations ◽  
Memory Function ◽  
Relaxation Phenomena ◽  
Stieltjes Function ◽  
Infinitely Divisible ◽  
Spectral Functions ◽  
Debye Relaxation ◽  
Relaxation Functions

In this paper, we show that spectral functions relevant for commonly used models of the non-Debye relaxation are related to the Stieltjes functions supported on the positive semi-axis. Using only this property, it can be shown that the response and relaxation functions are non-negative. They are connected to each other and obey the time evolution provided by integral equations involving the memory function M(t), which is the Stieltjes function as well. This fact is also due to the Stieltjes character of the spectral function. Stochastic processes-based approach to the relaxation phenomena gives the possibility to identify the memory function M(t) with the Laplace (Lévy) exponent of some infinitely divisible stochastic processes and to introduce its partner memory k(t). Both memories are related by the Sonine equation and lead to equivalent evolution equations which may be freely interchanged in dependence of our knowledge on memories governing the process.

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