scholarly journals Microwave Properties of Ferromagnetic Nanowires and Applications to Tunable Devices

2009 ◽  
Vol 152-153 ◽  
pp. 389-393 ◽  
Author(s):  
Judith Spiegel ◽  
Isabelle Huynen
Keyword(s):  
Magnetic Field ◽  
Dielectric Properties ◽  
External Magnetic Field ◽  
Filling Factor ◽  
Microwave Properties ◽  
Microwave Devices ◽  
Microwave Circuit ◽  
Broad Bandwidth ◽  
Ferromagnetic Nature ◽  
The One

Microwave devices as circulators or tunable filters demand nowadays small size and broad bandwidth. Ferromagnetic nanowired membranes are ideal candidates for this purpose. This paper focuses on the dielectric properties of such substrates, as influenced by the ferromagnetic nature of nanowires and their filling factor. Two particular cases are considered: a membrane filled up to its top with nanowires, forming a one-layer substrate, and a membrane filled up to a certain percentage of its height with nanowires, forming a two-layer substrate. The models proposed in this paper for each case take the inductive and gyromagnetic effects in the wires into account. They predict for the one-layer case a magnetodielectric behavior which is tunable by applying an external magnetic field. The effect is no longer visible for the two-layer topology corresponding to microwave circuit applications.

scholarly journals The Symmetry of Pairing and The Electromagnetic Properties of A Superconductor with A Four-Fermion Attraction at Zero Temperature

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1358
Author(s):  
Przemyslaw Tarasewicz
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Pairing Symmetry ◽  
Electromagnetic Properties ◽  
Electromagnetic Response ◽  
Cooper Pairs ◽  
Zero Temperature ◽  
Fermion System ◽  
Phonon Field ◽  
The One

Properties of a fermion system at zero temperature are investigated. The physical system is described by a Hamiltonian containing the BCS interaction and an attractive four-fermion interaction. The four-fermion potential is caused by attractions between Cooper pairs mediated by the phonon field. In this paper, the BCS interaction is assumed to be negligible and the four-fermion potential is the only one that acts in the system. The effect of the pairing symmetry used in the four-fermion potential on some zero-temperature properties is studied. This especially concerns the electromagnetic response of the system to an external magnetic field. It turns out that, in this instance, there are serious differences between the conventional BCS system and the one investigated in this paper.

NEUTRINOS IN EXTREMELY STRONG MAGNETIC FIELDS

2000 ◽  
Vol 15 (04) ◽  
pp. 523-534
Author(s):  
A. PÉREZ MARTÍNEZ ◽  
H. PÉREZ ROJAS ◽  
D. OLIVA AGÜERO ◽  
A. AMÉZAGA HECHAVARRÍA ◽  
S. RODRÍGUEZ ROMO
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fields ◽  
Threshold Energy ◽  
Strong Magnetic Fields ◽  
Self Energy ◽  
Loop Approximation ◽  
The One ◽  
The Magnetic Field ◽  
Thermal Background

We compute the dispersion curves for neutrinos propagating in a very dense electroweak plasma, in magnetic fields of order [Formula: see text]. The neutrino self-energy is calculated in the one-loop approximation. The dispersion equation is solved for motion parallel and perpendicular to the external magnetic field. We obtain an effective neutrino mass which increases with the magnetic field, up to values B where threshold energy for creation of W± pairs (out from the thermal background) is reached.

scholarly journals TEMPERATURE DEPENDENCE OF SPIN CURRENTS CARRIED BY JORDAN–WIGNER FERMIONS AND MAGNONS IN INSULATORS

2012 ◽  
Vol 26 (01) ◽  
pp. 1250011
Author(s):  
KOUKI NAKATA
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Temperature Dependence ◽  
Magnetic Field Gradient ◽  
Particle Interaction ◽  
Three Dimensional ◽  
Spin Current ◽  
One Dimensional ◽  
Spin Currents ◽  
The One

The temperature dependence of spin currents in insulators at the finite temperature near zero Kelvin is theoretically studied. The spin currents are carried by Jordan–Wigner fermions and magnons in one- and three-dimensional insulators. These spin currents are generated by the external magnetic field gradient along the quantization axis and also by the two-particle interaction gradient. In one-dimensional insulators, quantum fluctuations are strong and the spin current carried by Jordan–Wigner fermions shows the stronger dependence on temperatures than the one by magnons.

scholarly journals Boric acid in magnetized water: clean and powerful media for synthesis of 3,4-dihydropyrimidin-2(1H)-ones

RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 22751-22755
Author(s):  
Vahid Khakyzadeh ◽  
Ahmad Reza Moosavi-Zare ◽  
Sahra Sheikhaleslami ◽  
Amir Ehsani ◽  
Salbin Sediqi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Boric Acid ◽  
Condensation Reaction ◽  
One Pot ◽  
Magnetized Water ◽  
The One ◽  
First Time

Water was magnetized via an external magnetic field and employed, for the first time, as a solvent in green preparation of 3,4-dihydropyrimidin-2(1H)-ones by the one-pot three-component condensation reaction using boric acid as a catalyst.

scholarly journals Structural, Magnetic and Microwave Characterization of Polycrystalline Z-Type Sr3Co2Fe24O41 Hexaferrite

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2355
Author(s):  
Svetoslav Kolev ◽  
Petya Peneva ◽  
Kiril Krezhov ◽  
Tanya Malakova ◽  
Chavdar Ghelev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Sol Gel ◽  
Peak Frequency ◽  
Magnetic Phase Transitions ◽  
Microwave Properties ◽  
Zero Field ◽  
Auto Combustion ◽  
Dramatic Rise ◽  
Absorbing Material

We report results on the structural and microwave properties and magnetic phase transitions in polycrystalline Sr3Co2Fe24O41 hexaferrite synthesized by sol-gel auto-combustion and acting as a filler in a composite microwave absorbing material. The zero-field-cooled (ZFC) and field-cooled (FC) magnetization curves revealed a change in the magnetization behavior at 293 K. The reflection losses in the 1–20 GHz range of the Sr3Co2Fe24O41 powder dispersed homogeneously in a polymer matrix of silicon rubber were investigated in both the absence and presence of a magnetic field. In the latter case, a dramatic rise in the attenuation was observed. The microwave reflection losses reached the maximum value of 32.63 dB at 17.29 GHz in the Ku-band. The sensitivity of the microwave properties of the composite material to the external magnetic field was manifested by the appearance of new reflection losses maxima. At a fixed thickness tm of the composite, the attenuation peak frequency can be adjusted to a certain value either by changing the filling density or by applying an external magnetic field.

scholarly journals EXACT GROUND STATE WAVE FUNCTIONS FOR N ANYONS IN A MAGNETIC FIELD ON A TORUS

1993 ◽  
Vol 08 (33) ◽  
pp. 3173-3185 ◽  
Author(s):  
ANSAR FAYYAZUDDIN
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Ground State ◽  
Filling Factor ◽  
Wave Functions ◽  
State Wave ◽  
Exact Ground State ◽  
Lowest Landau Level ◽  
Complete Set ◽  
Chern Simons

The complete set of ground state wave functions for N anyons in an external magnetic field on the torus is found. The cases when the filling factor is less than or equal to one are considered. The single valued description of anyons is employed throughout by coupling bosons to a Chern-Simons field. At the end, the Chern-Simons interaction is removed by a singular gauge transformation as a result of which the wave functions become multi-component in agreement with other studies. It is shown that for statistics of the type θ=πq/p the exactly filled lowest Landau level has a q-fold degeneracy. Statistics of type π/p, which are relevant for the Laughlin theory of the FQHE, are singled out as those with non-degenerate filled ground states.

Theory of Nonequilibrium Thermodynamics With Application to the Transport Processes in a Solid

1966 ◽  
Vol 88 (1) ◽  
pp. 57-61 ◽  
Author(s):  
M. R. El-Saden
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Nonequilibrium Thermodynamics ◽  
Three Dimensional ◽  
Transport Processes ◽  
Coupled Processes ◽  
Heat Current ◽  
One Dimensional ◽  
Electrical Phenomenon ◽  
The One

The theory of nonequilibrium thermodynamics for inherently irreversible coupled processes is presented and the concept of heat is incorporated appropriately. The theory was applied to the problem of a solid carrying electric and heat currents in the presence of an external magnetic field. The principle of increase of entropy was employed to determine the reversibility or irreversibility of the macroscopic effects involved and to determine the limits on the material’s properties. The dynamic equations show that, in the one-dimensional thermoelectric case, the heat current is not coupled to the electrical phenomenon. In two and three-dimensional cases, the heat current is coupled to the electrical phenomenon only through the influence of the external magnetic field. Areas of disagreement with the literature are pointed out and discussed.

scholarly journals Моделирование критического состояния слоистых сверхпроводящих структур с неоднородными слоями

2021 ◽  
Vol 63 (10) ◽  
pp. 1471
Author(s):  
П.И. Безотосный ◽  
К.А. Дмитриева
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Critical Current ◽  
Layered Structures ◽  
Pinning Force ◽  
Ginzburg Landau ◽  
Number Of Layers ◽  
Ginzburg Landau Equations ◽  
The One ◽  
The Magnetic Field

An approach for calculating the critical state of layered structures consisting of inhomogeneous superconducting layers is proposed. The method is based on the numerical solution of the one-dimensional Ginzburg-Landau equations, generalized for an inhomogeneous plate. The method allows one to obtain the dependence of the critical current on the magnetic field, as well as the distribution of the current and magnetic field over the layers. A comparison is made of the averaged critical current of layered structures consisting of both inhomogeneous and homogeneous layers. It was found that with a relatively small number of layers and a small external magnetic field, the critical current of layered structures with homogeneous layers can exceed the critical current of structures with inhomogeneous layers. With an increase in the number of layers and / or the value of the external magnetic field, the critical current of layered structures with inhomogeneous layers begins, on the contrary, to exceed the critical current of structures with homogeneous layers. The pinning force in structures with inhomogeneous layers is higher than in the case of homogeneous ones.

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