A SIMPLE THEORY OF PHOTOFIELD EMISSION FROM THE SURFACE OF A METAL

2005 ◽  
Vol 19 (19) ◽  
pp. 3141-3149 ◽  
Author(s):  
R. K. THAPA ◽  
GUNAKAR DAS
Keyword(s):  
Differential Equation ◽  
Matrix Element ◽  
Simple Model ◽  
Fermi Level ◽  
Free Electron ◽  
State Energy ◽  
Transmission Probability ◽  
Initial State ◽  
The Matrix ◽  
Electron Wavefunction

A simple model calculation of photofield emission is presented in which the photofield emission current (PFEC) is calculated for metal W. The matrix element for photoexcitation is evaluated by using the free electron wavefunction. The transmission probability D(W) is deduced by solving Airy's differential equation. The variation of PFEC is studied as a function of parameters like the applied high electric field, the photon energy, the initial state energy with reference to the Fermi level. It is found that in addition to D(W), the matrix element Mfi also has effect on the photofield emission.

PHOTOEMISSION CALCULATION WITH A SIMPLE MODEL FOR THE PHOTON FIELD: APPLICATION TO ALUMINIUM

1991 ◽  
Vol 05 (01) ◽  
pp. 65-72 ◽  
Author(s):  
P. DAS ◽  
R.K. THAPA ◽  
N. KAR
Keyword(s):  
Experimental Data ◽  
Simple Model ◽  
Fermi Level ◽  
Dielectric Function ◽  
Cross Sections ◽  
Free Electron ◽  
Surface Region ◽  
Field Application ◽  
Frequency Dependent ◽  
Photon Field

Photoemission cross-sections are calculated, using a simple “local” dielectric function for computing the photon field in the surface region and free electron wavefunctions. Comparisons are made with the experimental data for the frequency-dependent normal photoemission from the Fermi level of aluminium, and the importance of the variation of the photon field in the surface region is pointed out.

Transverse Shubnikov–de Haas effect and the manifestation of quantum diffraction

2020 ◽  
Vol 34 (05) ◽  
pp. 2050016
Author(s):  
Yu. A. Berezhnoy ◽  
A. S. Molev
Keyword(s):  
Matrix Element ◽  
Electron Transition ◽  
Amplitude Distribution ◽  
Fraunhofer Diffraction ◽  
Initial State ◽  
Final State ◽  
Quantum Diffraction ◽  
The Matrix ◽  
Transverse Conductivity ◽  
Haas Effect

A quantum diffraction interpretation of the transverse Shubnikov–de Haas effect is presented. Within the framework of the conventional theory of this effect, we show that the matrix element for the electron transition from an initial state to a final state used in calculating the transverse electrical conductivity can be represented as a diffraction-type amplitude distribution. The squared modulus of this matrix element under certain conditions exhibits the Fraunhofer diffraction pattern. It is shown that the oscillating part of the transverse conductivity has the same form as the amplitude for Fraunhofer diffraction by an annular aperture.

scholarly journals High-temperature superconductivity using a model of hydrogen bonds

2018 ◽  
Vol 115 (22) ◽  
pp. 5709-5713 ◽  
Author(s):  
Daniel Kaplan ◽  
Yoseph Imry
Keyword(s):  
High Temperature ◽  
Matrix Element ◽  
Simple Model ◽  
Hydrogen Bonds ◽  
Isotope Effect ◽  
High Temperature Superconductivity ◽  
High Temperature Superconductors ◽  
Superconducting Gap ◽  
Gap Equation ◽  
The Matrix

Recently, there has been much interest in high-temperature superconductors and more recently in hydrogen-based superconductors. This work offers a simple model that explains the behavior of the superconducting gap based on naive BCS (Bardeen–Cooper–Schrieffer) theory and reproduces most effects seen in experiments, including the isotope effect and Tc enhancement as a function of pressure. We show that this is due to a combination of the factors appearing in the gap equation: the matrix element between the proton states and the level splitting of the proton.

scholarly journals Optimization Algorithm of Matrix Riccati Differential Equation and Application

2011 ◽  
Vol 2-3 ◽  
pp. 801-806
Author(s):  
Xiang Lin Hou ◽  
De Sheng Huang ◽  
Cong Chen
Keyword(s):  
Differential Equation ◽  
Matrix Element ◽  
Optimization Method ◽  
Control Parameters ◽  
Riccati Differential Equation ◽  
Dynamic Design ◽  
Design Variables ◽  
The Matrix ◽  
New Thinking ◽  
Riccati Matrix

To the matrix Riccati differential equation, based on dynamic design Variables Optimization Method, making unknown element of Riccati matrix as design variables, square sum of defined summation matrix element as objective function, a kind of new optimization Method about element of Riccati matrix orders is built. Universal program is formed. Practical examples are computed. Effectiveness is shown through result. The method is a new thinking for computing high order matrix Riccati Differential equation and obtaining control parameters.

PHOTOFIELD EMISSION CALCULATIONS BY USING PROJECTION OPERATOR METHOD

2007 ◽  
Vol 21 (22) ◽  
pp. 1501-1507
Author(s):  
R. K. THAPA ◽  
GUNAKAR DAS ◽  
S. R. GURUNG ◽  
B. I. SHARMA ◽  
P. K. PATRA
Keyword(s):  
Wave Function ◽  
Group Theory ◽  
Matrix Element ◽  
Projection Operator ◽  
Operator Method ◽  
Emission Current Density ◽  
Initial State ◽  
Projection Operator Method ◽  
The Matrix ◽  
Dependent Vector

A model calculation of photofield emission is discussed in which initial state wave function has been deduced by using projection operator method of group theory. A spatial dependent vector potential is used to evaluate the matrix element for calculating the photofield emission current density.

PHOTOEMISSION STUDIES OF THE Pt3Cr(110) SURFACE

1994 ◽  
Vol 01 (04) ◽  
pp. 641-644 ◽  
Author(s):  
R.B. PATEL ◽  
A.J. LIDDIARD ◽  
M.D. CRAPPER
Keyword(s):  
Electronic Structure ◽  
Binding Energy ◽  
Band Structure ◽  
Fermi Level ◽  
Free Electron ◽  
Initial State ◽  
Final State

Angle-resolved photoemission has been used to investigate the electronic structure of Pt 3 Cr . Experimental band structure has been calculated assuming a free-electron final state. Constant initial state measurements indicate that Pt and Cr d-bands both lie between the Fermi level and 7 eV binding energy.

scholarly journals Publisher Correction: Resonant phase-matching between a light wave and a free-electron wavefunction

2021 ◽  
Author(s):  
Raphael Dahan ◽  
Saar Nehemia ◽  
Michael Shentcis ◽  
Ori Reinhardt ◽  
Yuval Adiv ◽  
...  
Keyword(s):  
Free Electron ◽  
Light Wave ◽  
Phase Matching ◽  
Electron Wavefunction

scholarly journals ηQ Meson Photoproduction in Ultrarelativistic Heavy Ion Collisions

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Gong-Ming Yu ◽  
Gao-Gao Zhao ◽  
Zhen Bai ◽  
Yan-Bing Cai ◽  
Hai-Tao Yang ◽  
...  
Keyword(s):  
Heavy Ion Collisions ◽  
Hadron Collider ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Heavy Quarkonium ◽  
Color Singlet ◽  
Initial State ◽  
Color Octet ◽  
Ion Collisions ◽  
The Matrix

The transverse momentum distributions for inclusive ηc,b meson described by gluon-gluon interactions from photoproduction processes in relativistic heavy ion collisions are calculated. We considered the color-singlet (CS) and color-octet (CO) components within the framework of Nonrelativistic Quantum Chromodynamics (NRQCD) in the production of heavy quarkonium. The phenomenological values of the matrix elements for the color-singlet and color-octet components give the main contribution to the production of heavy quarkonium from the gluon-gluon interaction caused by the emission of additional gluon in the initial state. The numerical results indicate that the contribution of photoproduction processes cannot be negligible for midrapidity in p-p and Pb-Pb collisions at the Large Hadron Collider (LHC) energies.

Modeling Valence-Band Images from Synchrotron-Radiation Studies Using Display Analyzers: Lithium Fluoride and Graphite

1994 ◽  
Vol 375 ◽  
Author(s):  
Eric L. Shirley ◽  
Louis J. Terminello ◽  
John E. Klepeis ◽  
F. J. Himpsel
Keyword(s):  
Synchrotron Radiation ◽  
Band Structure ◽  
Lithium Fluoride ◽  
State Energy ◽  
Bragg Diffraction ◽  
Angular Distributions ◽  
Initial State ◽  
Statistical Comparison ◽  
Photoelectron Angular Distributions ◽  
Initial Crystal

AbstractWe present simulated photoelectron angular distributions (PAD's) for LiF and graphite. The results describe electron photocurrent versus photon energy, electron initial-state energy, and emission angles (leading to identification of two, or three, components of a valence electron's initial crystal momentum). Results are displayed in a fashion greatly facilitated by display analyzers. Earlier experimental results for LiF are confirmed in great detail. We discuss statistical comparison of theoretical and experimental PAD's. Effects of Bragg- diffraction on outgoing photoelectrons and uncertainty in crystal momentum normal to a surface are analyzed. In graphite, the observed lowering of symmetry, from that in a periodic-zone band structure to that seen in the PAD's, is modeled and explained.

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