scholarly journals Incoherent hydrodynamics of density waves in magnetic fields

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Aristomenis Donos ◽  
Christiana Pantelidou ◽  
Vaios Ziogas
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Finite Temperature ◽  
Chemical Potential ◽  
Density Wave ◽  
Density Waves ◽  
Hydrodynamic Modes ◽  
Momentum Relaxation ◽  
Effective Theories ◽  
The Magnetic Field

Abstract We use holography to derive effective theories of fluctuations in spontaneously broken phases of systems with finite temperature, chemical potential, magnetic field and momentum relaxation in which the order parameters break translations. We analytically construct the hydrodynamic modes corresponding to the coupled thermoelectric and density wave fluctuations and all of them turn out to be purely diffusive for our system. Upon introducing pinning for the density waves, some of these modes acquire not only a gap, but also a finite resonance due to the magnetic field. Finally, we study the optical properties and perform numerical checks of our analytical results. A crucial byproduct of our analysis is the identification of the correct current which describes the transport of heat in our system.

scholarly journals Enhancement of Galactic Dynamos by Density Waves

1990 ◽  
Vol 140 ◽  
pp. 127-130 ◽  
Author(s):  
Makoto Tosa ◽  
Masashi Chiba
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Density Wave ◽  
Wave Perturbation ◽  
Density Waves ◽  
Dynamo Action ◽  
Galactic Dynamos ◽  
The Magnetic Field ◽  
Effects Of Density

We examine effects of density waves on the local galactic αω-dynamo. Oscillations of the magnetic field and the dynamo parameters due to the density wave perturbation irreversibly couple with the dynamo action to enhance the growth of the magnetic fields.

COLLECTIVE FIELD THEORY TO MAGNETIC-FIELD-INDUCED SPIN-DENSITY-WAVE-STATE IN BECHGAARD SALTS, (TMTSF)2X

1993 ◽  
Vol 07 (19) ◽  
pp. 3415-3421 ◽  
Author(s):  
ALEXANDRE S. ROZHAVSKY
Keyword(s):  
Magnetic Field ◽  
Spin Density ◽  
Chemical Potential ◽  
Density Wave ◽  
Spin Density Wave ◽  
Hall Conductivity ◽  
Chiral Anomaly ◽  
Threshold Field ◽  
Wave State ◽  
Extended States

A field description of spin-density-wave (SDW) in a quasi-two-dimensional metal with open Fermi surface in magnetic field, is proposed. The SDW transition temperature, T c (H), and the Hall conductivity σxy, are calculated. The dependence T c (H) is found to be different from that of the Bardeen-Cooper-Schrieffer model, in particular, a threshold field, H c , found its natural explanation. It is proved that the quantized Hall conductivity arises from the chiral anomaly terms in the effective action provided there is pinning of chemical potential in the gap of extended states.

scholarly journals Magnetophonons & type-B Goldstones from hydrodynamics to holography

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Matteo Baggioli ◽  
Sebastian Grieninger ◽  
Li Li
Keyword(s):  
Magnetic Field ◽  
2D Materials ◽  
Goldstone Boson ◽  
Quasinormal Modes ◽  
Effective Field ◽  
Zero Magnetic Field ◽  
Type B ◽  
Hydrodynamic Modes ◽  
Pinning Mechanism ◽  
The Magnetic Field

Abstract We perform a detailed analysis of a large class of effective holographic models with broken translations at finite charge density and magnetic field. We exhaustively discuss the dispersion relations of the hydrodynamic modes at zero magnetic field and successfully match them to the predictions from charged hydrodynamics. At finite magnetic field, we identify the presence of an expected type-B Goldstone boson Re[ω] ∼ k2, known as magnetophonon and its gapped partner — the magnetoplasmon. We discuss their properties in relation to the effective field theory and hydrodynamics expectations. Finally, we compute the optical conductivities and the quasinormal modes at finite magnetic field. We observe that the pinning frequency of the magneto-resonance peak increases with the magnetic field, in agreement with experimental data on certain 2D materials, revealing the quantum nature of the holographic pinning mechanism.

High magnetic field NMR investigation of the spin density wave phase of TMTSF2PF6

2002 ◽  
Vol 12 (9) ◽  
pp. 389-389
Author(s):  
W. G. Clark ◽  
F. Zamborsky ◽  
B. Alavi ◽  
P. Vonlanthen ◽  
W. Moulton ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Spin Density ◽  
Density Wave ◽  
Spin Density Wave ◽  
Proton Relaxation ◽  
High Magnetic Fields ◽  
Organic Conductor ◽  
First Order ◽  
The Magnetic Field ◽  
Very High

We report proton NMR measurements of the effect of very high magnetic fields up to 44.7 T (1.9 GHz) on the spin density wave (SDW) transition of the organic conductor TMTSF2PF6. Up to 1.8 GHz, no effect of critical slowing close to the transition is seen on the proton relaxation rate (1/T1), which is determined by the SDW fluctuations associated with the phase transition at the NMR frequency. Thus, the correlation time for such fluctuations is less than $1O^{-10}$s. A possible explanation for the absence of longer correlation times is that the transition is weakly first order, so that the full critical divergence is never achieved. The measurements also show a dependence of the transition temperature on the orientation of the magnetic field and a quadratic dependence on its magnitude that agrees with earlier transport measurements at lower fields. The UCLA part of this work was supported by NSF Grant DMR-0072524.

scholarly journals Equation of State of a Magnetized Dense Neutron System

Universe ◽  
2019 ◽  
Vol 5 (5) ◽  
pp. 104 ◽  
Author(s):  
Efrain J. Ferrer ◽  
Aric Hackebill
Keyword(s):  
Magnetic Field ◽  
Equation Of State ◽  
Chemical Potential ◽  
Compact Objects ◽  
Field Direction ◽  
Neutron Density ◽  
Magnetic Field Direction ◽  
System Equation ◽  
The One ◽  
The Magnetic Field

We discuss how a magnetic field can affect the equation of state of a many-particle neutron system. We show that, due to the anisotropy in the pressures, the pressure transverse to the magnetic field direction increases with the magnetic field, while the one along the field direction decreases. We also show that in this medium there exists a significant negative field-dependent contribution associated with the vacuum pressure. This negative pressure demands a neutron density sufficiently high (corresponding to a baryonic chemical potential of μ = 2.25 GeV) to produce the necessary positive matter pressure that can compensate for the gravitational pull. The decrease of the parallel pressure with the field limits the maximum magnetic field to a value of the order of 10 18 G, where the pressure decays to zero. We show that the combination of all these effects produces an insignificant variation of the system equation of state. We also found that this neutron system exhibits paramagnetic behavior expressed by the Curie’s law in the high-temperature regime. The reported results may be of interest for the astrophysics of compact objects such as magnetars, which are endowed with substantial magnetic fields.

BIREFRINGENCE AND MAGNETO-OPTICAL PROPERTIES IN OLEIC ACID COATED Fe3O4 NANOPARTICLES: APPLICATION FOR OPTICAL SWITCH

2011 ◽  
Vol 10 (03) ◽  
pp. 515-520 ◽  
Author(s):  
SI-HUA XIA ◽  
JUN WANG ◽  
ZHANG-XIAN LU ◽  
FEIYAN ZHANG
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Oleic Acid ◽  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Optical Switch ◽  
Colloidal Suspension ◽  
Experimental Parameters ◽  
Nanoparticle Chains ◽  
The Magnetic Field

We report magneto-optical properties in a kerosene colloidal suspension of oleic acid coated Fe3O4 nanoparticles (~14 nm). The magnetic colloids (fluids) show birefringence under a magnetic field. Systematical studies of the on–off switch times upon application of the on–off magnetic field with varied experimental parameters indicate that the switch response time depends strongly on the strength of the magnetic field and the concentration of the magnetic nanoparticles in the fluid. The data can be explained in terms of the formation of magnetic nanoparticle chains under a magnetic field. The important magneto-optical properties of the magnetic fluids allow us to design a tunable optical switch.

Effect of the magnetic field on optical properties of GaN/AlN multiple quantum wells

2013 ◽  
Vol 134 ◽  
pp. 88-95 ◽  
Author(s):  
M. Solaimani ◽  
Morteza Izadifard ◽  
H. Arabshahi ◽  
Sarkardei Mohammad Reza
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Quantum Wells ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
The Magnetic Field
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