scholarly journals Regularization of the Nambu–Jona-Lasinio model under a uniform magnetic field and the role of the anomalous magnetic moments

2020 ◽  
Vol 102 (9) ◽  
Author(s):  
R. M. Aguirre
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Magnetic Moments

THE EINSTEIN–BRILLOUIN–KELLER ACTION QUANTIZATION FOR DIRAC FERMIONS

2011 ◽  
Vol 25 (08) ◽  
pp. 537-549 ◽  
Author(s):  
P. ONORATO
Keyword(s):  
Magnetic Field ◽  
Carbon Nanostructures ◽  
Uniform Magnetic Field ◽  
Graphene Nanoribbons ◽  
Maslov Index ◽  
Transverse Magnetic ◽  
Dirac Fermions ◽  
Integral Calculus ◽  
Classical Trajectories

The Einstein–Brillouin–Keller semiclassical quantization and the topological Maslov index are used to compute the electronic structure of carbon based nanostructures with or without transverse magnetic field. The calculation is based on the Dirac Fermions approach in the limit of strong coupling for the pseudospin. The electronic bandstructure for carbon nanotubes and graphene nanoribbons are discussed, focusing on the role of the chirality and of the unbonded edges configuration respectively. The effects of a transverse uniform magnetic field are analyzed, the different kinds of classical trajectories are discussed and related to the corresponding energies. The development is concise, transparent, and involves only elementary integral calculus and provides a conceptual and intuitive introduction to the quantum nature of carbon nanostructures.

ON THE APPLICATION OF PLASMA KINETIC THEORY TO IONIC SOUND-WAVE EXPERIMENTS IN MAGNETIC FIELDS

1965 ◽  
Vol 43 (10) ◽  
pp. 1750-1765 ◽  
Author(s):  
M. J. Haggerty
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Critical Frequency ◽  
Magnetic Field Intensity ◽  
Sound Waves ◽  
Cyclotron Radius ◽  
The Mean ◽  
The Magnetic Field ◽  
Theoretical Results

The kinetic theoretical results for a homogeneous plasma in a uniform magnetic field are discussed qualitatively. The role of the mean cyclotron radius as a natural long-range cutoff is clarified. A relationship between a critical frequency for ionic sound waves and the magnetic-field intensity is predicted.

Weak magnetohydrodynamic turbulence and intermittency

2015 ◽  
Vol 770 ◽  
Author(s):  
R. Meyrand ◽  
K. H. Kiyani ◽  
S. Galtier
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Three Dimensional ◽  
Leading Order ◽  
Magnetohydrodynamic Turbulence ◽  
Asymptotic Regime ◽  
Resonant Interactions ◽  
Vector Separation ◽  
Parallel Current

Three-dimensional numerical simulation is used to investigate intermittency in incompressible weak magnetohydrodynamic turbulence with a strong uniform magnetic field $\boldsymbol{b}_{\mathbf{0}}$ and zero cross-helicity. At leading order, this asymptotic regime is achieved via three-wave resonant interactions with the scattering of a wave on a 2D mode for which $k_{\Vert }=0$. When the interactions with the 2D modes are artificially reduced, we show numerically that the system exhibits an energy spectrum with $k_{\bot }^{-3/2}$, whereas the expected exact solution with $k_{\bot }^{-2}$ is recovered with the full nonlinear system. In the latter case, strong intermittency is found when the vector separation of structure functions is taken transverse to $\boldsymbol{b}_{\mathbf{0}}$. This result may be explained by the influence of the 2D modes whose regime belongs to strong turbulence. In addition to shedding light on the origin of this intermittency, we derive a log-Poisson law, ${\it\zeta}_{p}=p/8+1-(1/4)^{p/2}$, which fits the data perfectly and highlights the important role of parallel current sheets.

USING EVOLUTIONARY ALGORITHM TO CALCULATE THE GROUND-STATE ENERGY OF DOUBLE-ELECTRON ATOMS IN A UNIFORM MAGNETIC FIELD (B ≤ 109G)

2000 ◽  
Vol 11 (01) ◽  
pp. 183-194 ◽  
Author(s):  
LIANJUN LIU ◽  
LI ZHAO ◽  
YOUDONG MAO ◽  
DONG YU ◽  
JINGWEN XU ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Evolutionary Algorithm ◽  
Ground State Energy ◽  
Ground State ◽  
Uniform Magnetic Field ◽  
State Energy ◽  
Electron System ◽  
Energy Calculation ◽  
Double Electron

It is very difficult to calculate the accurate ground-state energies of the double-electron atom like helium in a uniform magnetic field. By using the modified configuration interaction (MCI) method and the evolutionary algorithm (EA), we obtained highly accurate results. We discuss the role of magnetic field in the ground state of the double-electron system and the possibility of variational ground-state energy calculation by using evolutionary algorithm directly. Results show that compared with other algorithms, such as the simplex method, EA is more efficient in calculating atomic energies, and can be used in other fields of physics.

scholarly journals Sum rules for an atomic hyperfine structure in a magnetic field

2006 ◽  
Vol 84 (9) ◽  
pp. 801-811
Author(s):  
Savely G Karshenboim
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Hyperfine Structure ◽  
Uniform Magnetic Field ◽  
Sum Rules ◽  
Magnetic Moments ◽  
Energy Levels ◽  
Linear Combinations ◽  
Nuclear Magnetic Moments ◽  
The Magnetic Field

The sum rules for the energy levels of a hyperfine multiplet in a constant uniform magnetic field are presented. It is found that for any value of the electron angular moment and the nuclear spin there are certain linear combinations of energy levels that do not depend on the magnetic field and can be used to determine the unperturbed hyperfine-structure separation in the presence of a perturbing magnetic field. It is also demonstrated that there are other linear combinations that are linear with the external magnetic field and hence can be used to determine bound values of the electron and nuclear magnetic moments. The accuracy of the approximation within which the result is valid is also discussed.PACS Nos.: 32.10.Fn, 32.60.+i1

scholarly journals On the Role of Magnetic Field Fluctuations in Diffusive Shock Acceleration

2011 ◽  
Vol 21 (3) ◽  
pp. 199
Author(s):  
Doan Kim The ◽  
Pham Tuan Anh ◽  
Pham Ngoc Diep ◽  
Pham Ngoc Dong ◽  
Nguyen Van Hiep ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Field Component ◽  
Larmor Radius ◽  
Shock Acceleration ◽  
Simultaneous Presence ◽  
Diffusive Shock Acceleration ◽  
Cosmic Particle ◽  
Field Fluctuations

A simple numerical simulation of the mechanism of diffusive shock acceleration, responsible for the acceleration of cosmic rays in the environment of young Super Nova Remnants, is presented. The relative roles of a uniform magnetic field component, inherited from the parent collapsed star, and of magnetic turbulences, known to be present in the vicinity of the shock, are investigated. It is shown that a uniform magnetic field allows for only doubling the energy of the cosmic particle. Important accelerations require the simultaneous presence of magnetic field turbulences at a scale commensurable with its Larmor radius.

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.

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.

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