Effect of geometrical shape in the cross section of quantum wires on exciton binding energy

1997 ◽  
Vol 82 (11) ◽  
pp. 5753-5757 ◽  
Author(s):  
A. Thilagam
Keyword(s):  
Binding Energy ◽  
Cross Section ◽  
Quantum Wires ◽  
Exciton Binding Energy ◽  
Geometrical Shape ◽  
The Cross

scholarly journals Magneto-Electric Effect on Guided Waves in Functionally Graded Piezoelectric–Piezomagnetic Fan-Shaped Cylindrical Structures

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2174 ◽  
Author(s):  
Bo Zhang ◽  
Jiangong Yu ◽  
Lahoucine Elmaimouni ◽  
Xiaoming Zhang
Keyword(s):  
Cross Section ◽  
Functionally Graded ◽  
Heaviside Function ◽  
Polynomial Method ◽  
Geometrical Shape ◽  
Cylindrical Structures ◽  
Geometric Size ◽  
The Cross ◽  
Functionally Graded Piezoelectric ◽  
Electric Effect

Functionally graded piezoelectric–piezomagnetic (FGPP) material simultaneously consists of piezomagnetic and piezoelectric phases, which are able to convert energy among mechanical, electric, and magnetic fields. The magneto-electric effect on waves in FGPP fan-shaped cylindrical structures is studied by exploiting the double Legendre orthogonal polynomial method. By means of the Heaviside function, the initial conditions are brought into wave motion equations. Dispersion properties, electric and magnetic potential, and the Poynting vector are calculated. Subsequently, the effect of the graded variation and geometric size on wave characteristics is analyzed. The FGPP fan-shaped cylindrical structures are of complex geometrical shape and material inhomogeneity, so their influences on the magneto-electric effect are the focus of discussion. Results reveal that the cut-off frequencies have a negative relationship with the cross-section area of the structure. The magneto-electric effect could be adjusted via altering the geometric size of the cross-section. These results can be utilized to design and optimize piezoelectric–piezomagnetic fan-shaped transducers.

UPS of a-Si:H: What is the energy of the Er 4f states?

2000 ◽  
Vol 609 ◽  
Author(s):  
Leandro R. Tessler ◽  
Cínthia Piamonteze ◽  
Ana Carola Iniguez ◽  
Abner de Siervo ◽  
Richard Landers ◽  
...  
Keyword(s):  
Binding Energy ◽  
Excitation Energy ◽  
Cross Section ◽  
Energy Gap ◽  
Valence States ◽  
Erbium Doped ◽  
Order Of Magnitude ◽  
Synchrotron Light ◽  
The Cross ◽  
Er Doped

ABSTRACTOne very important problem concerning erbium-doped silicon is the electronic structure of the Er3+ impurities. In particular, it is still not clear if the 4f levels can be treated as frozen core levels or their overlap with s and p states of their neighbors must be considered explicitly. For crystalline Si, the 4f levels have been supposed to be anywhere between 20 eV below the valence band and within the energy gap. In this paper we report on the first ultraviolet photoemission spectroscopy (UPS) measurements on Er-doped a-Si:H. Samples of a-Si:H<Er> with different Er contents (up to 1 at. % Er) were prepared by co-sputtering from a Si target partially covered with metallic Er platelets. In order to enhance the Er states relative to the Si and H states, the excitation energy was tuned between 40 and 140 eV with a synchrotron light source. At 140 eV excitation energy the cross-section of the Er 4f and 5p states is more than an order of magnitude higher than the cross section of the Si 3s or 3p states. As the Er concentration increases, a shoulder and then a peak appears at 10.0±0.5 eV binding energy. The intensity and width of this peak is well correlated with the Er concentration, and with the Er 5p and 5p½ levels at 26 and 32 eV binding energy, respectively. We attribute the peak at 10.0±0.5 eV binding energy to the Er 4f level. These are the only occupied states that can be related to the presence of Er, indicating that these levels are not valence states and consequently can be treated as frozen core levels.

scholarly journals Exciton Binding Energy in GaAs V-Shaped Quantum Wires

1994 ◽  
Vol 73 (21) ◽  
pp. 2899-2902 ◽  
Author(s):  
R. Rinaldi ◽  
R. Cingolani ◽  
M. Lepore ◽  
M. Ferrara ◽  
I. M. Catalano ◽  
...  
Keyword(s):  
Binding Energy ◽  
Quantum Wires ◽  
Exciton Binding Energy

scholarly journals The angular distribution of protons projected by fast neutrons

1937 ◽  
Vol 163 (913) ◽  
pp. 265-281 ◽  
Keyword(s):  
Angular Distribution ◽  
Binding Energy ◽  
Cross Section ◽  
Direct Evidence ◽  
Fast Neutrons ◽  
Proton Scattering ◽  
Potential Well ◽  
The Mean ◽  
The Cross ◽  
Square Hole

The nature of the interaction between neutron and proton has assumed great importance in modern nuclear theory, since it is now generally assumed that these two particles form the fundamental constituents of all nuclei. Little direct evidence exists, however, as to the nature of this interaction. The stable existence of the deuteron shows that the force between neutron and proton is attractive, and for purposes of calculation a “square hole” potential well has generally been assumed. With this model some success has been obtained* in correlating the magnitudes of a number of experimentally measurable quantities such as ( a ) the binding energy of the deuteron, ( b ) the total cross-section for neutron-proton scattering (Tuve and Hafstad 1936; Amaldi and Fermi 1936 a ), ( c ) the cross-section for photo­ electric disintegration of the deuteron (Chadwick and Goldhaber 1935), and ( d ) the cross-section for capture of neutrons by protons (Amaldi and Fermi 1936 b ). The interaction is not completely derivable from the above data, since the values of these quantities depend mainly upon r 2 V , where r is the mean radius and V is the depth of the potential hole.

Exciton binding energy in T-shaped semiconductor quantum wires

1997 ◽  
Vol 56 (15) ◽  
pp. 9235-9238 ◽  
Author(s):  
S. N. Walck ◽  
T. L. Reinecke ◽  
P. A. Knipp
Keyword(s):  
Binding Energy ◽  
Quantum Wires ◽  
Exciton Binding Energy
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