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Magnetoconductivity in Weyl semimetals: Effect of chemical potential and temperature
We present the detailed analyses of magneto-conductivities in a Weyl
semimetal within Born and self-consistent Born approximations. In the presence
of the charged impurities, the linear magnetoresistance can happen when the
charge carriers are mainly from the zeroth (n=0) Landau level. Interestingly,
the linear magnetoresistance is very robust against the change of temperature,
as long as the charge carriers mainly come from the zeroth Landau level. We
denote this parameter regime as the high-field regime. On the other hand, the
linear magnetoresistance disappears once the charge carriers from the higher
Landau levels can provide notable contributions. Our analysis indicates that
the deviation from the linear magnetoresistance is mainly due to the deviation
of the longitudinal conductivity from the behavior. We found two
important features of the self-energy approximation: 1. a dramatic jump of
, when the Landau level begins to contribute charge
carriers, which is the beginning point of the middle-field regime, when
decreasing the external magnetic field from high field; 2. In the low-field
regime shows a behavior and results the
magnetoresistance to show a behavior. The detailed and
careful numerical calculation indicates that the self-energy approximation
(including both the Born and the self-consistent Born approximations) does not
explain the recent experimental observation of linear magnetoresistance in Weyl
semimetals.Comment: The accepted version. Extending the previous version by including the
discussions of self-consistent Born approximatio
Laser Field Induced Birefringence and Enhancement of Magneto-optical Rotation
An initially isotropic medium, when subjected to either a magnetic field or a
coherent field, can induce anisotropy in the medium and can cause the
polarization of a probe field to rotate. Therefore the rotation of probe
polarization, due to magnetic field alone, can be controlled efficiently with
the use of a coherent control field. We demonstrate this enhancement of the
magneto-optical rotation (MOR) of a linearly polarized light, by doing detailed
calculations on a system with relevant transitions .Comment: 9 pages including 4 Figure
Dispersion and transitions of dipolar plasmon modes in graded plasmonic waveguides
Coupled plasmon modes are studied in graded plasmonic waveguides, which are
periodic chains of metallic nanoparticles embedded in a host with gradually
varying refractive indices. We identify three types of localized modes called
"light", "heavy", and "light-heavy" plasmonic gradons outside the passband,
according to various degrees of localization. We also demonstrate new
transitions among extended and localized modes when the interparticle
separation is smaller than a critical , whereas the three types of
localized modes occur for , with no extended modes. The transitions can
be explained with phase diagrams constructed for the lossless metallic systems.Comment: Preliminary results have been presented at ETOPIM 7. Submitted to
Appl. Phys. Let
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