On the motion of quantized electric flux lines and nonexistence of magnetic monopoles

1965 ◽  
Vol 35 (4) ◽  
pp. 1236-1239
Author(s):  
G. Cavalleri
Keyword(s):  
Magnetic Monopoles ◽  
Flux Lines ◽  
Electric Flux

Ultrastructural Kinetics of Electrically Induced Fusion of Human Erythrocytes

1985 ◽  
Vol 43 ◽  
pp. 494-495
Author(s):  
D.A. Stenger
Keyword(s):  
Electrical Breakdown ◽  
Freeze Fracture ◽  
Kinetic Mechanism ◽  
Eukaryotic Cell ◽  
Copper Sample ◽  
Human Erythrocytes ◽  
Flux Lines ◽  
Latex Beads ◽  
Electric Flux ◽  
Kinetics Of

Conditions for electrical breakdown and subsequent fusion of biological membranes have been reported for a variety of eukaryotic cell systems. Large fusion yields may be obtained by first causing cells to form pearl chains parallel to the electric flux lines in a high frequency a.c. field by a process known as dielectrophoresis. The dielectrophoretic force affords close positioning of the cells and facilitates maintenance and expansion of intercellular membrane and cytoplasmic contiguity initiated by one or more sharp square pulses directed through the pearl chains. Reversible disruption of the cell membrane occurs when the compressive electrical force caused by the square pulse exceeds a critical value.This investigation focused on elucidating the ultrastructural kinetic mechanism(s) involved in the electrically-induced fusion of human erythrocytes. In this case, rapid freeze copper sample holders for freeze-fracture were incorporated as electrodes into a circuit capable of performing the type of protocol described above (Fig. 1). Washed human erythrocytes were suspended in 0.3 M sucrose containing 25.7 μm latex beads for electrode separation.

Xenon ion irradiation of superconducting YBa2Cu3O7 thin films

1990 ◽  
Vol 48 (4) ◽  
pp. 92-93
Author(s):  
H. Watanabe ◽  
B. Kabius ◽  
B. Roas ◽  
K. Urban
Keyword(s):  
Defect Formation ◽  
Ion Irradiation ◽  
High Resolution Electron Microscopy ◽  
Structural Disorder ◽  
Flux Lines ◽  
Pinning Effect ◽  
Magnetic Flux Lines ◽  
Resolution Electron ◽  
Radiation Induced ◽  
Induced Defects

Recently it was reported that the critical current density(Jc) of YBa2Cu2O7, in the presence of magnetic field, is enhanced by ion irradiation. The enhancement is thought to be due to the pinning of the magnetic flux lines by radiation-induced defects or by structural disorder. The aim of the present study was to understand the fundamental mechanisms of the defect formation in association with the pinning effect in YBa2Cu3O7 by means of high-resolution electron microscopy(HRTEM).The YBa2Cu3O7 specimens were prepared by laser ablation in an insitu process. During deposition, a substrate temperature and oxygen atmosphere were kept at about 1073 K and 0.4 mbar, respectively. In this way high quality epitaxially films can be obtained with the caxis parallel to the <100 > SrTiO3 substrate normal. The specimens were irradiated at a temperature of 77 K with 173 MeV Xe ions up to a dose of 3.0 × 1016 m−2.

Real-time observation of vortex lattices in a superconductor

1993 ◽  
Vol 51 ◽  
pp. 1050-1051
Author(s):  
K. Harada ◽  
T. Matsuda ◽  
J.E. Bonevich ◽  
M. Igarashi ◽  
S. Kondo ◽  
...  
Keyword(s):  
Real Time ◽  
Flux Line ◽  
Electron Holography ◽  
Lorentz Microscopy ◽  
Vortex Lattices ◽  
Flux Lines ◽  
Magnetic Flux Lines ◽  
Time Observation ◽  
Thin Superconductor ◽  
Real Time Observation

Previous observations of magnetic flux-lines (vortex lattices) in superconductors, such as the field distribution of a flux-line, and flux-line dynamics activated by heat and current, have employed the high spatial resolution and magnetic sensitivity of electron holography. And recently, the 2-D static distribution of vortices was also observed by this technique. However, real-time observations of the vortex lattice, in spite of scientific and technological interest, have not been possible due to experimental difficulties. Here, we report the real-time observation of vortex lattices in a thin superconductor, by means of Lorentz microscopy using a 300 kV field emission electron microscope. This technique allows us to observe the dynamic motion of individual vortices and record the events on a VTR system.The experimental arrangement is shown in Fig. 1. A Nb thin film for transmission observation was prepared by chemical etching. The grain size of the film was increased by annealing, and single crystals were observed with a thickness of 50∼90 nm.

On the influence of specimen thickness in TEM images of super-conducting vortices

1996 ◽  
Vol 54 ◽  
pp. 724-725
Author(s):  
J. Bonevich ◽  
D. Capacci ◽  
G. Pozzi ◽  
K. Harada ◽  
H. Kasai ◽  
...  
Keyword(s):  
Flux Line ◽  
Analytical Form ◽  
Realistic Model ◽  
Electron Holography ◽  
Specimen Thickness ◽  
Flux Tubes ◽  
Analytical Expression ◽  
Flux Lines ◽  
Normal Core ◽  
Two Parameters

The successful observation of superconducting flux lines (fluxons) in thin specimens both in conventional and high Tc superconductors by means of Lorentz and electron holography methods has presented several problems concerning the interpretation of the experimental results. The first approach has been to model the fluxon as a bundle of flux tubes perpendicular to the specimen surface (for which the electron optical phase shift has been found in analytical form) with a magnetic flux distribution given by the London model, which corresponds to a flux line having an infinitely small normal core. In addition to being described by an analytical expression, this model has the advantage that a single parameter, the London penetration depth, completely characterizes the superconducting fluxon. The obtained results have shown that the most relevant features of the experimental data are well interpreted by this model. However, Clem has proposed another more realistic model for the fluxon core that removes the unphysical limitation of the infinitely small normal core and has the advantage of being described by an analytical expression depending on two parameters (the coherence length and the London depth).

The Added Value of Graphical Input and Display for Electron Lens Design

1990 ◽  
Vol 48 (1) ◽  
pp. 190-191
Author(s):  
B. Lencova ◽  
G. Wisselink
Keyword(s):  
Flux Density ◽  
Numerical Data ◽  
Added Value ◽  
Lens Design ◽  
Step Size ◽  
Magnetic Lens ◽  
Flux Lines ◽  
Fine Mesh ◽  
Electron Lens ◽  
User Friendly

Recent progress in computer technology enables the calculation of lens fields and focal properties on commonly available computers such as IBM ATs. If we add to this the use of graphics, we greatly increase the applicability of design programs for electron lenses. Most programs for field computation are based on the finite element method (FEM). They are written in Fortran 77, so that they are easily transferred from PCs to larger machines.The design process has recently been made significantly more user friendly by adding input programs written in Turbo Pascal, which allows a flexible implementation of computer graphics. The input programs have not only menu driven input and modification of numerical data, but also graphics editing of the data. The input programs create files which are subsequently read by the Fortran programs. From the main menu of our magnetic lens design program, further options are chosen by using function keys or numbers. Some options (lens initialization and setting, fine mesh, current densities, etc.) open other menus where computation parameters can be set or numerical data can be entered with the help of a simple line editor. The "draw lens" option enables graphical editing of the mesh - see fig. I. The geometry of the electron lens is specified in terms of coordinates and indices of a coarse quadrilateral mesh. In this mesh, the fine mesh with smoothly changing step size is calculated by an automeshing procedure. The options shown in fig. 1 allow modification of the number of coarse mesh lines, change of coordinates of mesh points or lines, and specification of lens parts. Interactive and graphical modification of the fine mesh can be called from the fine mesh menu. Finally, the lens computation can be called. Our FEM program allows up to 8000 mesh points on an AT computer. Another menu allows the display of computed results stored in output files and graphical display of axial flux density, flux density in magnetic parts, and the flux lines in magnetic lenses - see fig. 2. A series of several lens excitations with user specified or default magnetization curves can be calculated and displayed in one session.

Magnetoresistance due to scattering on the flux lines in a superconductor-insulator-semiconductor multilayer

1991 ◽  
Vol 1 (8) ◽  
pp. 1165-1171 ◽  
Author(s):  
D. A. Kuptsov ◽  
M. Yu. Moiseev
Keyword(s):  
Flux Lines

Existence of magnetic monopoles in higher dimensions is analogous to unipolar gravity

2020 ◽  
Author(s):  
Deep Bhattacharjee
Keyword(s):  
Flux Density ◽  
Higher Dimensions ◽  
Closed Surface ◽  
Magnetic Monopoles ◽  
Surface Integral ◽  
Flux Tubes ◽  
Spatial Dimensions ◽  
Net Flux ◽  
Field Lines ◽  
The Universe

Gravity has been leaking in higher dimensions in the bulk. Gravity being a closed string is not attached or does not have any endpoints unlike photons to any Dirichlet (p)-Branes and therefore can travel inter-dimensional without any hindrance. In LHC, CERN, Gravitons are difficult to detect as they last for such a short span of time and in most of the cases invisible as because they can escape to higher spatial dimensions to the maximum of 10, as per 'M'-Theory. Gravity being one of the 4-Fundamental forces is weaker than all 3 (strong and weak nuclear force, electromagnetism) and therefore a famous problem has been made in particle physics called the 'hierarchy problem'. Through comprehensive analysis and research I have come to the conclusion that if dimension is 5 (or 4 if we neglect the temporal dimensions) then an old approach is there for the compactification of the dimensions as per Kaluza-Klein theory and the most important implications of this theory is that an unification of electromagnetism with gravitation occurs in the fifth dimensions, therefore we can conclude that both the charge (electric as well as magnetic and gravity) are dependent of each other in case of Dimensions greater than 4 (5 if time is added). Now, basic principles of electromagnetic theory states that the field-flux density through a closed surface like a T 2 Torus when integrated over the surface area leads to a zero flux. That means there is no flux outside this closed surface integral. However, if the surface is open then the field flux density is not zero and this preserves the concept of magnetic monopoles. However, in a paper in 1931,[1] Dirac approaches monopole theory of magnetism through a different perspectives that, if all the electrical charges of the universe is quantized[2] then there is a suitable (not yet proved though) existence of monopoles; however this are not well understood as of today's scenario. In condensed matter physics, plasma physics and magneto hydrodynamics, there are flux tubes and as the both ends of the flux tubes are independent of each other then the net flux through the cylinder is zero as the amount of field lines entering the tube on one side is equal to the amount of field lines exit from the other end. And in the sides of the cylinder or the flux tube there is no escape of field lines, hence, net flux is conserved. There also exists a type of 'Quasiparticles' that can act as a monopole.[3][4][5] Now, from the perspectives of the Guess law of electromagnetism, if there exists a magnetic monopole then the net charge or flux density over a surface is not zero rather the divergence of the flux density B is 4 [6]and an alternative approach of the 'monopole' can be achieved by increasing the spatial dimensions by a factor of 1 or more. The Gravity has no such poles and therefore can be considered as a unipolar flux density existing throughout the universe and is applicable to the inverse square law of decreasing magnitude via distance as 1/r 2. However, a magnet is always of bipolar with a north and South Pole. If a magnet can be broken then also the broken parts develop the other poles and become bipolar. However, there are tiny domains inside a magnet and if a magnet can be heated to approx. 700℃ then all the poles disappeared and if its cooled quickly, rather very quickly then the tiny domains inside the magnet would not get enough time to rearrange themselves and multipolar magnet is developed therefore to preserve the bipolar properties, the magnet should be cooled slowly allowing the time given to the tiny domains top rearrange themselves. Therefore, even multipole can be achieved quite easily but not the monopoles. So, the equation for a closed surface integral of a flux density without monopole is ∯(S) B dS = 0 or ∇ • B = 0 and that closed surface can be considered as 2 types namely (we will discuss about torus) as because in string theory compactification of higher spatial dimensions occurs in torus.

scholarly journals Comment on “Massive electrodynamics and the magnetic monopoles”

2021 ◽  
Vol 103 (12) ◽  
Author(s):  
Michael Dunia ◽  
Timothy J. Evans ◽  
Douglas Singleton
Keyword(s):  
Magnetic Monopoles
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