scholarly journals On the Neutron Transition Magnetic Moment

Physics ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 271-289 ◽  
Author(s):  
Zurab Berezhiani ◽  
Riccardo Biondi ◽  
Yuri Kamyshkov ◽  
Louis Varriano
Keyword(s):  
Magnetic Field ◽  
Magnetic Moment ◽  
Potential Role ◽  
Magnetic Moments ◽  
Lifetime Measurement ◽  
Neutron Lifetime ◽  
Transition Magnetic Moment ◽  
Average Probability ◽  
The Magnetic Field

We discuss the possibility of the transition magnetic moments (TMM) between the neutron n and its hypothetical sterile twin “mirror neutron” n′ from a parallel particle “mirror” sector. The neutron can be spontaneously converted into mirror neutron via the TMM (in addition to the more conventional transformation channel due to n−n′ mass mixing) interacting with the magnetic field B as well as with mirror magnetic field B′. We derive analytic formulae for the average probability of n−n′ conversion and consider possible experimental manifestations of neutron TMM effects. In particular, we discuss the potential role of these effects in the neutron lifetime measurement experiments leading to new, testable predictions.

3D Monte Carlo Simulations of Aggregate Structures in a Magnetic Colloidal Suspension Composed of Plate-Like Particles With Magnetic Moment Normal to the Particle Axis

2010 ◽  
Author(s):  
Yasuhiro Sakuda ◽  
Masayuki Aoshima ◽  
Akira Satoh
Keyword(s):  
Magnetic Field ◽  
Monte Carlo ◽  
Applied Magnetic Field ◽  
Magnetic Moment ◽  
Magnetic Particle ◽  
Colloidal Suspension ◽  
Magnetic Moments ◽  
Particle Interactions ◽  
Aggregate Structures ◽  
The Magnetic Field

We have investigated the internal aggregate structures of a colloidal suspension composed of magnetic plate-like particles with a magnetic moment normal to the particle axis by means of three-dimensional Monte Carlo simulations. In concrete, we have attempted to clarify the influences of the magnetic field strength, magnetic interactions between particles, and volumetric fraction of particles, on particle aggregation phenomena. In order to discuss quantitatively the aggregate structures of particles, we have focused on the radial distribution and orientational pair correlation function. For no applied magnetic field cases, long column-like clusters are formed as magnetic particle-particle interactions increase. Characteristics of these clusters are that particles incline in a certain direction with their magnetic moments alternating in direction between the neighboring particles. For applied magnetic field cases, the magnetic moments of the particles incline in the magnetic field direction, so that the columnar clusters are not formed. The brick wall-like aggregates are formed as the influences of the magnetic field and magnetic particle-particle interactions become significantly dominant.

New Features of the Freezing Vortex Matter in Single Crystals of YBa2Cu3O7-δ

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3326-3329
Author(s):  
A. I. Rykov ◽  
S. Tajima ◽  
F. V. Kusmartsev
Keyword(s):  
Magnetic Field ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
Freezing Temperature ◽  
Vortex Matter ◽  
Local Moments ◽  
Flux Lines ◽  
Dipolar Contribution ◽  
First Order Transition ◽  
The Magnetic Field

We report on the new features observed in the magnetization of a high-T c superconductor at cooling through the first order transition. The single crystal of YB2Cu3O 7-δ cooled in the magnetic field H‖c at cooling (FCC) exhibits a multipolar magnetic moment which results from the summing up over the sample of both the negative (magnetization of the uncompressed vortex lattice) and the positive local magnetic moments. The positive local moments correspond to the enhanced density of the trapped flux lines exceeding locally that for the external magnetic field. At large fields (> 3T) below freezing temperature Tf, the dipolar contribution into the magnetic moment is fully reversible, in agreement with zero density of critical current. The magnetization of the field-cooled sample measured at warming (FCW) exhibit jumps at clearly larger temperature Tm(>Tf). The jump from zero to a finite value in the octupolar magnetizations [Formula: see text] occurs at the same temperatures Tf, Tm as the conventional jump in the field-cooled dipolar magnetization [Formula: see text] related to the vortex ordering entropy (ΔS < k B ). The high-pole magnetic moments are metastable and exhibit long sample-specific relaxation, quickest in a narrow temperature range at T<Tm close to Tm.

scholarly journals MAGNETIC-FIELD-INDUCED SUPERCONDUCTIVITY IN LAYERED ORGANIC MOLECULAR CRYSTALS WITH LOCALIZED MAGNETIC MOMENTS

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3071-3071
Author(s):  
O. CEPAS ◽  
R. H. MCKENZIE ◽  
J. MERINO
Keyword(s):  
Magnetic Field ◽  
Superconducting State ◽  
Magnetic Moments ◽  
Spin Fluctuations ◽  
Zero Field ◽  
Field Range ◽  
Organic Molecular Crystals ◽  
Magnetic Ions ◽  
The Magnetic Field

The synthetic organic compound λ (BETS) 2 FeCl 4 undergoes successive transitions from an antiferromagnetic insulator to a metal and then to a superconductor as a magnetic field is increased. We use a Hubbard-Kondo model to clarify the role of the Fe 3+ magnetic ions in these phase transition. In the high-field regime, the magnetic field acting on the electron spins is compensated by the exchange field He due to the magnetic ions. This suggests that the field-induced superconducting state is the same as the zero-field superconducting state which occurs under pressure or when the Fe 3+ ions are replaced by non-magnetic Ga 3+ ions. We show how Hc can be extracted from the observed splitting of the Shybnikov-de Haas frequencies. Furthermore, we use this method of extracting He to predict the field range for field-induced superconductivity in other materials. We also show that at high fields the spin fluctuations of the localized spins are not important.

scholarly journals What Density of Magnetosheath Sodium Ions Can Provide the Observed Decrease in the Magnetic Field of the “Double Magnetopause” during the First MESSENGER Flyby?

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1168
Author(s):  
Elena Belenkaya ◽  
Ivan Pensionerov
Keyword(s):  
Magnetic Field ◽  
Analytical Approach ◽  
Field Structure ◽  
Sodium Ions ◽  
Plasma Parameters ◽  
Calculation Results ◽  
Magnetizing Current ◽  
The Magnetic Field ◽  
Density Excess

On 14 January 2008, the MESSENGER spacecraft, during its first flyby around Mercury, recorded the magnetic field structure, which was later called the “double magnetopause”. The role of sodium ions penetrating into the Hermean magnetosphere from the magnetosheath in generation of this structure has been discussed since then. The violation of the symmetry of the plasma parameters at the magnetopause is the cause of the magnetizing current generation. Here, we consider whether the change in the density of sodium ions on both sides of the Hermean magnetopause could be the cause of a wide diamagnetic current in the magnetosphere at its dawn-side boundary observed during the first MESSENGER flyby. In the present paper, we propose an analytical approach that made it possible to determine the magnetosheath Na+ density excess providing the best agreement between the calculation results and the observed magnetic field in the double magnetopause.

Connecting a Star’s Convection Zone with its Corona

1995 ◽  
Vol 12 (2) ◽  
pp. 180-185 ◽  
Author(s):  
D. J. Galloway ◽  
C. A. Jones
Keyword(s):  
Magnetic Field ◽  
Convection Zone ◽  
Flux Rope ◽  
Field System ◽  
Stellar Convection ◽  
Coronal Activity ◽  
Flux Concentration ◽  
Global Understanding ◽  
The Magnetic Field

AbstractThis paper discusses problems which have as their uniting theme the need to understand the coupling between a stellar convection zone and a magnetically dominated corona above it. Interest is concentrated on how the convection drives the atmosphere above, loading it with the currents that give rise to flares and other forms of coronal activity. The role of boundary conditions appears to be crucial, suggesting that a global understanding of the magnetic field system is necessary to explain what is observed in the corona. Calculations are presented which suggest that currents flowing up a flux rope return not in the immediate vicinity of the rope but rather in an alternative flux concentration located some distance away.

The role of slow magnetostrophic waves in dipole formation in rapidly rotating dynamos

2021 ◽  
Author(s):  
Aditya Varma ◽  
Binod Sreenivasan
Keyword(s):  
Magnetic Field ◽  
Threshold Value ◽  
Dipole Field ◽  
Wave Frequency ◽  
Alfven Wave ◽  
Inertial Waves ◽  
Axial Dipole ◽  
Wide Range ◽  
The Magnetic Field

&lt;p&gt;It is known that the columnar structures in rapidly rotating convection are affected by the magnetic field in ways that enhance their helicity. This may explain the dominance of the axial dipole in rotating dynamos. Dynamo simulations starting from a small seed magnetic field have shown that the growth of the field is accompanied by the excitation of convection in the energy-containing length scales. Here, this process is studied by examining axial wave motions in the growth phase of the dynamo for a wide range of thermal forcing. In the early stages of evolution where the field is weak, fast inertial waves weakly modified by the magnetic field are abundantly present. As the field strength(measured by the ratio of the Alfven wave to the inertial wave frequency) exceeds a threshold value, slow magnetostrophic waves are spontaneously generated. The excitation of the slow waves coincides with the generation of helicity through columnar motion, and is followed by the formation of the axial dipole from a chaotic, multipolar state. In strongly driven convection, the slow wave frequency is attenuated, causing weakening of the axial dipole intensity. Kinematic dynamo simulations at the same parameters, where only fast inertial waves are present, fail to produce the axial dipole field. The dipole field in planetary dynamos may thus be supported by the helicity from slow magnetostrophic waves.&lt;/p&gt;

scholarly journals Chiral Magneto-Electrochemistry

2018 ◽  
Vol 4 (3) ◽  
pp. 36 ◽  
Author(s):  
Anup Kumar ◽  
Prakash Mondal ◽  
Claudio Fontanesi
Keyword(s):  
Magnetic Field ◽  
Experimental Studies ◽  
Spin Accumulation ◽  
Chiral Molecules ◽  
Electrochemical System ◽  
Ferromagnetic Electrodes ◽  
Spin Polarized ◽  
The Magnetic Field ◽  
Research Domain

Magneto-electrochemistry (MEC) is a unique paradigm in science, where electrochemical experiments are carried out as a function of an applied magnetic field, creating a new horizon of potential scientific interest and technological applications. Over time, detailed understanding of this research domain was developed to identify and rationalize the possible effects exerted by a magnetic field on the various microscopic processes occurring in an electrochemical system. Notably, until a few years ago, the role of spin was not taken into account in the field of magneto-electrochemistry. Remarkably, recent experimental studies reveal that electron transmission through chiral molecules is spin selective and this effect has been referred to as the chiral-induced spin selectivity (CISS) effect. Spin-dependent electrochemistry originates from the implementation of the CISS effect in electrochemistry, where the magnetic field is used to obtain spin-polarized currents (using ferromagnetic electrodes) or, conversely, a magnetic field is obtained as the result of spin accumulation.

Morphology of the magnetic field near Mars and the role of the magnetic crustal anomalies: Dayside region

2008 ◽  
Vol 56 (6) ◽  
pp. 852-855 ◽  
Author(s):  
E. Kallio ◽  
R.A. Frahm ◽  
Y. Futaana ◽  
A. Fedorov ◽  
P. Janhunen
Keyword(s):  
Magnetic Field ◽  
The Magnetic Field
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