Cubic magnetic response of diamagnetic molecules via third-order electronic current density

2020 ◽  
Vol 153 (23) ◽  
pp. 234112
Author(s):  
Paolo Lazzeretti
1966 ◽  
Vol 145 (2) ◽  
pp. 507-518 ◽  
Author(s):  
H. Michael Gilder ◽  
David Lazarus

2018 ◽  
Author(s):  
Michihiro Okuyama ◽  
Fumihiko Sakata

<div>In studying a dynamical process of the chemical reaction, it is decisive to get appropriate information from an electronic current density. To this end, we divide one-body electronic density into a couple of densities, that is, an electronic sharing density and an electronic contraction density. Since the one-body electronic current density defi ned directly through the microscopic electronic wave function gives null value under the Born-Oppenheimer molecular dynamics, we propose to employ the Maxwell's displacement current density de fined by means of the one-body electronic density obtained under the same approximation. Applying the electronic sharing and the electronic contraction current densities to a hydrogen molecule, we show these densities give important physical quantities for analyzing a dynamical process of the covalent bond.</div>


1994 ◽  
Vol 313 (3) ◽  
pp. 299-304 ◽  
Author(s):  
P. Lazzeretti ◽  
M. Malagoli ◽  
R. Zanasi

1993 ◽  
Vol 48 (1-2) ◽  
pp. 134-136
Author(s):  
N. Sukumar ◽  
B. M. Deb ◽  
Harjinder Singh

Some consequences of the quantum fluid dynamics formulation are discussed for excited states of atoms and molecules and for time-dependent processes. It is shown that the conservation of electronic current density j(r) allows us to manufacture a gauge potential for each excited state of an atom, molecule or atom in a molecule. This potential gives rise to a tube of magnetic flux carried around by the many-electron system. In time-dependent situations, the evolution of the electronic density distribution can be followed with simple, site-dependent cellular automaton (CA) rules. The CA consists of a lattice of sites, each with a finite set of possible values, here representing finite localized elements of electronic charge and current density (since the charge density rno longer suffices to fully characterize a time-dependent system, it needs to be supplemented with information about the current density j).Our numerical results are presented elsewhere and further developmentis in progress.


Fowler and Nordheimj- and Oppenheimerj have already independently studied the theory of the emission of electrons from cold metals under the effect of an intense electric field, and have obtained results in good qualitative agreement with experiment. The formula for this “ auto-electronic ” current density, —I, obtained by the former authors is I = ε/2 πh μ 1/2 / ( X + μ ) X 1/2 F 2 e -4/3 kX 3/2 / F (1) at ordinary temperatures. In this formula k 2 = 8 π 2 m/h 2 ; μ is the parameter of the metallic electron distribution in the Fermi-Dirac statistics; X is the thermionic work function for the metal; — ε is the charge on the electron; h is Planck’s constant and — F is the derivative of the potential energy of the electron along the outward normal at the cathode surface; I, F and ε are then all positive. When the unit of energy is the electron-volt and the unit of current density is amperes per square centimetre this reduces to I = 6.2 x 10 -6 μ 1/2 / ( X + μ ) X 1/2 F 2 e -6.8 x 10 7 X 3/2 / F (2)


10.14311/578 ◽  
2004 ◽  
Vol 44 (3) ◽  
Author(s):  
M. Horák

Potential barriers of different types (rectangular, triangle, parabolic) with a dc-bias and a small ac-signal in the THz-frequency band are investigated in this paper. The height of the potential barrier is modulated by the high frequency signal. If electrons penetrate through the barrier they can emit or absorb usually one or even more energy quanta, thus the electron wave function behind the barrier is a superposition of different harmonics. The time-dependent Schrödinger equation is solved to obtain the reflection and transmission amplitudes and the barrier transmittance corresponding to the harmonics. The electronic current density is calculated according to the Tsu-Esaki formula. If the harmonics of the electron current density are known, the complex admittance and other electrical parameters of the structure can be found.


1950 ◽  
Vol 28b (9) ◽  
pp. 541-550 ◽  
Author(s):  
A. J. Dekker ◽  
Helen M. A. Urquhart

Porous aluminum oxide layers may be obtained by anodic oxidation in sulphuric acid. The base of the pores is separated from the metal by a thin insulating barrier layer. The experiments show that the ultimate thickness of the barrier layer remains constant after a critical value has been reached. The dependence of the final thickness on current density, concentration, and temperature has been investigated. It is suggested that an electronic current is involved in the mechanism which limits the growth of the barrier layer.


1983 ◽  
Vol 28 (2) ◽  
pp. 559-566 ◽  
Author(s):  
J. A. N. F. Gomes

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