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.

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 Vortex guide under a Lorentz force

2020 ◽  
pp. 101-106
Author(s):  
C. A. Aguirre ◽  
Q. Martins ◽  
Jose Barba
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
External Magnetic Field ◽  
Lorentz Force ◽  
Vortex State ◽  
Cooper Pairs ◽  
Magnetic Response ◽  
External Current ◽  
Critical Temperatures ◽  
Ginzburg Landau

In the present work we studied the effect of the nature of the contacts, by which a weak external current is applied, in an anisotropic superconducting rectangle, on the magnetization, magnetic susceptibility, density of the Cooper pairs and  (magnetic field for which the first vortices entry on the sample). The contacts are simulates by the  parameter, and the anisotropy is present in sections with different critical temperatures modeling for  function, both in the Ginzburg-Landau formalis. Also, the sample is embebbed in an external magnetic field . We established how the nature of the contacts and the presence of a weak Lorentz Force, influence the magnetic response and the vortex state of the sample.

scholarly journals A magnetoactive metamaterial based on a structured ferrite

2021 ◽  
Vol 26 (1) ◽  
pp. 28-34
Author(s):  
S. Polevoy ◽  
◽  
G. Kharchenko ◽  
S. Tarapov ◽  
O. Kravchuk ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Frequency Dependence ◽  
Static Magnetic Field ◽  
Groove Depth ◽  
Electromagnetic Properties ◽  
Saturation Field ◽  
External Static Magnetic Field ◽  
Spatial Geometry ◽  
Field Strengths

Subject and Purpose. The use of spatially structured ferromagnets is promising for designing materials with unique predetermined electromagnetic properties welcome to the development of magnetically controlled microwave and optical devices. The paper addresses the electromagnetic properties of structured ferrite samples of a different shape (spatial geometry) and is devoted to their research by the method of electron spin resonance (ESR). Methods and methodology. The research into magnetic properties of structured ferrite samples was performed by the ESR method. The measurements of transmission coefficient spectra were carried out inside a rectangular waveguide with an external magnetic field applied. Results. We have experimentally shown that over a range of external magnetic field strengths, the frequency of the ferromagnetic resonance (FMR) of grooved ferrite samples (groove type spatial geometry) increases with the groove depth. The FMR frequency depends also on the groove orientation relative to the long side of the sample. We have shown that as the external static magnetic field approaches the saturation field of the ferrite, the FMR frequency dependence on the external static magnetic field demonstrates "jump-like" behavior. And as the magnetic field exceeds the ferrite saturation field, the FMR frequency dependence on the groove depth gets a monotonic character and rises with the further growth of the field strength. Conclusion. We have shown that the use of structured ferrites as microwave electronics components becomes reasonable at magnetic field strengths exceeding the saturation field of the ferrite. At these fields, such a ferrite offers a monotonically increasing dependence of the resonant frequency on the external magnetic field and on the depth of grooves on the ferrite surface. Structured ferrites are promising in the microwave range as components of controlled filters, polarizers, anisotropic ferrite resonators since they can provide predetermined effective permeability and anisotropy

The electromagnetic response of a fermion system at zero temperature

2009 ◽  
Vol 72 (1) ◽  
pp. 25-39
Author(s):  
P. Tarasewicz ◽  
A. Jasionowski ◽  
A. Świa̧tek
Keyword(s):  
Electromagnetic Response ◽  
Zero Temperature ◽  
Fermion System

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.

MINIMAL EXECUTION TIME OF SHOR'S ALGORITHM AT LOW TEMPERATURES

2009 ◽  
Vol 07 (01) ◽  
pp. 287-296
Author(s):  
M. A. AVILA
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Execution Time ◽  
Low Temperatures ◽  
Quantum Computer ◽  
Common Belief ◽  
Zero Temperature ◽  
Decoherence Time ◽  
Shor's Algorithm ◽  
The Common

The minimal time, T Shor , in which a one-way quantum computer can execute Shor's algorithm is derived. In the absence of an external magnetic field, this quantity diverges at very small temperatures. This result coincides with that of Anders et al. obtained simultaneously to ours but using thermodynamical arguments. Such divergence contradicts the common belief that it is possible to do quantum computation at low temperatures. It is shown that in the presence of a weak external magnetic field, T Shor becomes a quantized quantity which vanishes at zero temperature. Decoherence is not a problem because T Shor /τ dec < 10-9, where τdec is decoherence time.

UHF-Properties of Nanocomposites: Magnetic Resonance

2015 ◽  
Vol 1084 ◽  
pp. 66-71 ◽  
Author(s):  
Alexander Bagdasarian ◽  
Mikhail Samoylovich ◽  
Alpik Mkrtchyan ◽  
Anatoly Rinkevich ◽  
Alexey Belyanin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
External Magnetic Field ◽  
Wavelength Range ◽  
Electromagnetic Properties ◽  
Reflection Coefficients ◽  
Nanocomposite Particles ◽  
Millimeter Wavelength ◽  
Transmission And Reflection Coefficients ◽  
Transmission And Reflection

This work presents the results of studies of electromagnetic properties of nanocomposites based on opal matrices in the millimeter wavelength range. It is shown that the application of an external magnetic field changes the transmission and reflection coefficients. Magnetic resonance was studied in nanocomposite particles of spinel ferrites or metals. Magnetic resonance spectra were restored. We considered the parameters of nanocomposites required for using in microwave devices.

scholarly journals Development of a high temperature printable composite for microwave absorption applications

2021 ◽  
Vol 8 (5) ◽  
pp. 739-747
Author(s):  
Leticia Martinez ◽  
◽  
Den Palessonga ◽  
Philippe Roquefort ◽  
Alexis Chevalier ◽  
...  
Keyword(s):  
High Temperature ◽  
Fused Deposition Modeling ◽  
Low Cost ◽  
Temperature Stability ◽  
Polyphenylene Sulfide ◽  
Electromagnetic Properties ◽  
Electromagnetic Response ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
The One

<abstract> <p>This study deals with the development of a printable composite material based on a polyphenylene sulfide (PPS) matrix and carbonyl iron (Fe) particles, with controlled electromagnetic performance. More specifically, materials were simultaneous melt mixed and shaped under the form of filament with a diameter suitable for Fused Deposition Modeling. After reminding the potentialities of the printable PPS matrix, especially in terms of temperature resistance, microwave characterizations were performed on toroidal samples. The measured electromagnetic properties were compatible with absorption applications and compared to those of a commercial iron-filled PolyLactic Acid (PLA). Rectangular waveguide microwave loads were designed and fabricated by Fused Deposition Modeling with both materials. The PPS-Fe load has a volume that is 7 times lower than the PLA-Fe load due to a higher permittivity-permeability product and losses. Heat treatments demonstrated that no degradation is observed for the PPS-Fe load up to 180 ℃ while the PLA-Fe load is totally melted at 150 ℃. In the same time, it was observed that the maximum power supported by the PPS-Fe load is three times higher than the one supported by the PLA-Fe load. Finally, the temperature stability of the electromagnetic response of the PPS-Fe composite was demonstrated by measurements in the −70 ℃ to 140 ℃ temperature range. This new high temperature printable composite paves the way to the development of efficient, low-cost, low-weight, power and temperature stable absorbers for microwave applications.</p> </abstract>

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