scholarly journals Tunneling spectroscopy of Landau band gaps at a quantum Hall line junction with adjustable Fermi level

2006 ◽  
Vol 73 (20) ◽  
Author(s):  
Matthias Habl ◽  
Matthias Reinwald ◽  
Werner Wegscheider ◽  
Max Bichler ◽  
Gerhard Abstreiter
Keyword(s):  
Fermi Level ◽  
Quantum Hall ◽  
Tunneling Spectroscopy ◽  
Band Gaps ◽  
Landau Band

scholarly journals Tunneling spectroscopy of localized states near the quantum Hall edge

JETP Letters ◽  
2000 ◽  
Vol 72 (6) ◽  
pp. 333-336 ◽  
Author(s):  
A. Alekseev ◽  
V. Cheianov ◽  
A. P. Dmitriev ◽  
V. Yu. Kachorovski
Keyword(s):  
Quantum Hall ◽  
Tunneling Spectroscopy ◽  
Localized States

Generalized gauge invariance and the integer quantum Hall effect

1991 ◽  
Vol 432 (1884) ◽  
pp. 43-54 ◽  
Keyword(s):  
Quantum Hall Effect ◽  
Gauge Invariance ◽  
Periodic Potential ◽  
Quantum Hall ◽  
Winding Number ◽  
Hall Conductance ◽  
Integer Quantum Hall Effect ◽  
Integer Quantum ◽  
Landau Band ◽  
Invariance Argument

Generalizing a simple gauge-invariance argument, we introduce a k -space vector potential A k which allows us to obtain explicitly the identification of the Hall conductance with the quantized phase winding number of the wave function around the Brillouin zone. We also demonstrate, based on these winding number considerations alone, that a weak periodic potential which splits each Landau band into non-degenerate subbands results in Hall conductances which sum to unity, and satisfy a Diophantine equation.

STRUCTURAL AND ELECTRONIC EVOLUTION FROM SiC SHEET TO SILICENE

2013 ◽  
Vol 27 (32) ◽  
pp. 1350188 ◽  
Author(s):  
G. LIU ◽  
M. S. WU ◽  
C. Y. OUYANG ◽  
B. XU
Keyword(s):  
Density Functional Theory ◽  
Fermi Level ◽  
Density Of States ◽  
First Principles ◽  
Density Functional ◽  
Band Gaps ◽  
Functional Theory ◽  
Orbital Contribution ◽  
Structural And Electronic Properties ◽  
Substitution Ratio

The evolution of the structural and electronic properties from SiC sheet to silicene is studied by using first-principles density functional theory. It is found that the planar configurations of the Si – C monolayer systems are basically kept except for the increase of the buckling of the planar structure when the substitution ratio of Si increases. Band gaps of the Si – C monolayer system decrease gradually when the substitution ratio of Si atoms ranges from 0% to 100%. The energy and type of the band gaps are closely related with the substitution ratio of Si atoms and the Si – C order. Further analysis of density of states reveals the orbital contribution of Si and C atoms near the Fermi level. The discussion of the electronic evolution from SiC sheet to silicene would widen the application of the Si – C monolayer systems in the optoelectronic field in the future nanotechnology.

First-Principle Study of the Electronic and Optical Properties of Ti Doped ZnS

2012 ◽  
Vol 430-432 ◽  
pp. 173-176 ◽  
Author(s):  
Chang Peng Chen ◽  
Jian Xiong Xie ◽  
Jia Fu Wang
Keyword(s):  
Optical Properties ◽  
Fermi Level ◽  
Conduction Band ◽  
Electronic Structures ◽  
Density Functional ◽  
Band Gaps ◽  
First Principle ◽  
Level Shifts ◽  
Calculation Results ◽  
Impurity Elements

Based on the density functional pseudopotential method, the electronic structures and the optical properties for Ti doped ZnS are investigated in detail. The calculation results indicate that the doping of Ti widens the band gap of ZnS and the Fermi level shifts upward into the conduction band. The impurity elements form new highly localized impurity energy level at the bottom of the conduction band near the Fermi level.,.Meanwhile, blue shifts are revealed in both the imaginary part of dielectric function and the absorption spectra corresponding to the change of band gaps.

First-principles study on the electronic and magnetic properties of the Zn0.75Mo0.25M(M = S,Se,Te)

2016 ◽  
Vol 30 (19) ◽  
pp. 1650249 ◽  
Author(s):  
Zhu-Hua Yin ◽  
Jian-Min Zhang ◽  
Ke-Wei Xu
Keyword(s):  
Magnetic Properties ◽  
Fermi Level ◽  
First Principles ◽  
Atomic Radius ◽  
Band Gaps ◽  
First Principles Calculation ◽  
Spintronic Devices ◽  
Lattice Constants ◽  
Electronic And Magnetic Properties ◽  
Tetrahedral Crystal

The geometrical, electronic and magnetic properties of the Zn[Formula: see text]Mo[Formula: see text]M (M[Formula: see text]=[Formula: see text]S, Se and Te) have been studied by spin-polarized first-principles calculation. The optimized lattice constants of 5.535, 5.836 and 6.274 Å for M[Formula: see text]=[Formula: see text]S, Se and Te are related to the atomic radius of 1.09, 1.22 and 1.42 Å for S, Se and Te atoms, respectively. The Zn[Formula: see text]Mo[Formula: see text]M are magnetic half-metallic (HM) with the spin-down conventional band gaps of 2.899, 2.126 and 1.840 eV, while the HM band gaps of 0.393, 0.016 and 0.294 eV for M[Formula: see text]=[Formula: see text]S, Se and Te, respectively. At the Fermi level, the less than half-filled Mo-[Formula: see text] orbital hybridizated with the less M-[Formula: see text] orbital contributes only spin-up channel leading Zn[Formula: see text]Mo[Formula: see text]M an HM ferromagnetism. The tetrahedral crystal field formed by adjacent three Zn atoms and one M atom splits the spin-up channel (majority spin) of Mo-[Formula: see text] orbital into three-fold degenerate [Formula: see text] states at the Fermi level and double degenerate [Formula: see text] [Formula: see text] states below the Fermi level. The exchange splitting energies of the Zn[Formula: see text]Mo[Formula: see text]M are −2.611, −2.231 and −1.717 eV for M[Formula: see text]=[Formula: see text]S, Se and Te, respectively. The results provide an useful theoretical guidance for Zn[Formula: see text]Mo[Formula: see text]M applications in spintronic devices.

scholarly journals Possible existence of a band of extended states induced by inter-Landau-band mixing in a quantum Hall system

2006 ◽  
Vol 18 (6) ◽  
pp. 2029-2055 ◽  
Author(s):  
Gang Xiong ◽  
Shi-Dong Wang ◽  
Qian Niu ◽  
Yupeng Wang ◽  
X C Xie ◽  
...  
Keyword(s):  
Quantum Hall ◽  
Band Mixing ◽  
Extended States ◽  
Quantum Hall System ◽  
Landau Band
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