scholarly journals Stability of flat-band edge states in topological superconductors without inversion center

2014 ◽  
Vol 89 (5) ◽  
Author(s):  
Raquel Queiroz ◽  
Andreas P. Schnyder
Keyword(s):  
Band Edge ◽  
Flat Band ◽  
Edge States ◽  
Inversion Center ◽  
Topological Superconductors

Band-edge states in short-period (GaAs)m/(AlAs)nsuperlattices

1989 ◽  
Vol 39 (8) ◽  
pp. 5165-5174 ◽  
Author(s):  
Sudha Gopalan ◽  
N. E. Christensen ◽  
M. Cardona
Keyword(s):  
Band Edge ◽  
Edge States ◽  
Short Period

Ultrafast Carrier Dynamics, Optical Amplification, and Lasing in Nanocrystal Quantum Dots

MRS Bulletin ◽  
2001 ◽  
Vol 26 (12) ◽  
pp. 998-1004 ◽  
Author(s):  
Victor I. Klimov ◽  
Moungi G. Bawendi
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Quantum Wires ◽  
Electronic States ◽  
Three Dimensions ◽  
Band Edge ◽  
Lasing Threshold ◽  
Wide Energy Range ◽  
Band Edge Emission ◽  
Edge States

Semiconductor materials are widely used in both optically and electrically pumped lasers. The use of semiconductor quantum wells (QWs) as optical-gain media has resulted in important advances in laser technology. QWs have a two-dimensional, step-like density of electronic states that is nonzero at the band edge, enabling a higher concentration of carriers to contribute to the band-edge emission and leading to a reduced lasing threshold, improved temperature stability, and a narrower emission line. A further enhancement in the density of the band-edge states and an associated reduction in the lasing threshold are in principle possible using quantum wires and quantum dots (QDs), in which the confinement is in two and three dimensions, respectively. In very small dots, the spacing of the electronic states is much greater than the available thermal energy (strong confinement), inhibiting thermal depopulation of the lowest electronic states. This effect should result in a lasing threshold that is temperatureinsensitive at an excitation level of only 1 electron-hole (e-h) pair per dot on average. Additionally, QDs in the strongconfinement regime have an emission wavelength that is a pronounced function of size, adding the advantage of continuous spectral tunability over a wide energy range simply by changing the size of the dots.

scholarly journals Excitation to defect-bound band edge states in two-dimensional semiconductors and its effect on carrier transport

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Dan Wang ◽  
Dong Han ◽  
Damien West ◽  
Nian-Ke Chen ◽  
Sheng-Yi Xie ◽  
...  
Keyword(s):  
Carrier Transport ◽  
Band Edge ◽  
Two Dimensional ◽  
Edge States

On the “U-shaped” continuum of band edge states at the Si/SiO2 interface

2011 ◽  
Vol 99 (22) ◽  
pp. 223516 ◽  
Author(s):  
J. T. Ryan ◽  
R. G. Southwick ◽  
J. P. Campbell ◽  
K. P. Cheung ◽  
C. D. Young ◽  
...  
Keyword(s):  
Band Edge ◽  
Edge States

scholarly journals Characterizations of topological superconductors: Chern numbers, edge states and Majorana zero modes

2017 ◽  
Vol 19 (9) ◽  
pp. 093018 ◽  
Author(s):  
Xiao-Ping Liu ◽  
Yuan Zhou ◽  
Yi-Fei Wang ◽  
Chang-De Gong
Keyword(s):  
Edge States ◽  
Zero Modes ◽  
Topological Superconductors ◽  
Chern Numbers

THEORY OF THE CARRIER FERMI ENERGY AND DENSITY OF STATES OF n- and p-TYPE SnTe

2011 ◽  
Vol 25 (29) ◽  
pp. 4007-4020 ◽  
Author(s):  
R. K. DAS ◽  
S. MOHAPATRO
Keyword(s):  
Density Of States ◽  
Fermi Energy ◽  
Indirect Comparison ◽  
Orbit Interaction ◽  
Band Edge ◽  
Hamiltonian Matrix ◽  
Level Energy ◽  
Spin Orbit ◽  
Edge States ◽  
P Type

In the present work we theoretically develop a k⋅π model to calculate the carrier electronic structure for both n- and p-type SnTe . Here π is the momentum operator in the presence of the spin–orbit interaction. The work is an extension of the theory developed for n- and p- PbTe earlier by one of the authors to evaluate the Fermi energy and the density of states (DOS). We consider a six-level energy basis for SnTe , as proposed by Bernick and Kleinman. One set of calculations was done by diagonalizing the k⋅π Hamiltonian matrix for the band-edge states and treating the far bands using perturbation theory. In the second set we have rediagonalized the k⋅π Hamiltonian matrix for the band edge states, treating the first diagonalization as the basis. The far bands are, as usual, included through perturbation. We have compared the results of both the sets. Results obtained for n- and p-type SnTe are also compared with that of n- and p-type PbTe . The similarities and contrasts are discussed. An indirect comparison with the DOS of the metallic tin suggests that the calculations are fairly reasonable. The results are also compared with some recent results for SnTe .

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