arXiv subjects

Aya Kagimura

Publications and source records attributed to Aya Kagimura.

3 recordsLinked to original sources

arXiv2017

Intra-cone transition effect to magnetoconductivity in Dirac semimetal

We study the transport of the fermions with a small mass in the presence of Coulomb impurities, which could be realized in slightly distorted Dirac semimetals. Using the semiclassical Boltzmann equation, we derive the relaxation times for two kinds of intra-cone transition process. One is due to the effect of mass, and the other is due to the excited states in Landau levels under the weaker magnetic field. Hence we derive the mass dependence and the magnetic field dependence of the longitudinal magnetoconductivity in the presence of parallel electric and magnetic fields.

cond-mat.mes-hall↗

arXiv2015

Effective lattice action for the configurations smeared by the Wilson flow

We investigate a trajectory for the Wilson flow in the theory space. For this purpose, we determine the coefficient of the plaquette and rectangular terms in the action for the configurations defined by the solution of the Wilson flow. The demon method regarded as one of the inverse Monte Carlo methods is used for the determination of them. Starting from the conventional Wilson plaquette action of quenched QCD, we find that the coefficient of the plaquette grows while that of the rectangular tends to negative with the development of the flow as the known improved actions. We also find that the trajectory forms a straight line in the two-coupling theory space.

hep-lat↗

arXiv2015

Bosonization approach for "atomic collapse" in graphene

We study quantum electrodynamics with 2+1 dimensional massless Dirac fermion around a Coulomb impurity. Around a large charge with atomic number Z > 137, the QED vacuum is expected to collapse due to the strong Coulombic force. While the relativistic quantum mechanics fails to make reliable predictions for the fate of the vacuum, the heavy ion collision experiment also does not give clear understanding of this system. Recently, the "atomic collapse" resonances were observed on graphene where an artificial nuclei can be made. In this paper, we present our nonperturbative study of the vacuum structure of the quasiparticles in graphene with a charge impurity which contains multi-body effect using bosonization method.

hep-th↗