arXiv subjects

Andrés G. Jirón Vicente

Publications and source records attributed to Andrés G. Jirón Vicente.

5 recordsLinked to original sources

arXiv2023

Effects of a uniform magnetic field on twisted graphene nanoribbons

In the present work, the relativistic quantum motion of massless fermions in a helicoidal graphene nanoribbon under the influence of a uniform magnetic field is investigated. Considering a uniform magnetic field ($B$) aligned along the axis of helicoid, this problem is explored in the context of Dirac equation in a curved space-time. As this system does not support exact solutions due to considered background, the bound-state solutions and local density of state (LDOS) are obtained numerically by means of the Numerov method. The combined effects of width of the nanoribbon ($D$), length of ribbon ($L$), twist parameter ($ω$) and $B$ on the equations of motion and local density of states (LDOS) are analyzed and discussed. It is verified that the presence of $B$ produces a constant minimum value of local density of state on the axis of helicoid, which is possible only for values large enough of $ω$, in contrast to the case for $B=0$ already studied in the literature.

cond-mat.mes-hall↗

arXiv2023

Comment on "Relativistic quantum oscillator model under the effects of the violation of Lorentz symmetry by an arbitrary fixed vector field'' by Faizuddin Ahmed

We obtain the correct expressions for the energy and normalized eigenfunctions for a spin-zero relativistic quantum oscillator model under the violation of Lorentz symmetry defined by an arbitrary constant vector field $v^μ$.

quant-ph↗

arXiv2020

Remarks on thermodynamic properties of a double ring-shaped quantum dot at low and high temperatures

In a recent paper published in this Journal, Khordad and collaborators [J Low Temp Phys (2018) 190:200] have studied the thermodynamics properties of a GaAs double ring-shaped quantum dot under external magnetic and electric fields. In that meritorious research the energy of system was obtained by solving the Schrödinger equation. The radial equation was mapped into a confluent hypergeometric differential equation and the differential equation associated to $z$ coordinate was mapped into a biconfluent Heun differential equation. In this paper, it is pointed out a misleading treatment on the solution of the biconfluent Heun equation. It is shown that the energy $E_{z}$ can not be labeled with $n_{z}$ and this fact jeopardizes the results of this system. We calculate the partition function with the correct energy spectrum and recalculate the specific heat and entropy as a function of low and high temperatures.

cond-mat.mes-hall↗

arXiv2020

Comment on "Chern-Simons theory and atypical Hall conductivity in the Varma phase''

In a recent paper published in this Journal [Phys. Rev. B 97, 075135 (2018)], Menezes et al. analyze the topological behavior of a effective bosonic model defined on the Lieb lattice in presence of an electromagnetic field. In this context, the authors claim to have found an atypical quantum Hall effect for the quasiparticles. However, some inconsistencies related to the treatment of the propagator jeopardizes the main result in this system.

hep-th↗

arXiv2020

Comment on "Dirac fermions in Som-Raychaudhuri space-time with scalar and vector potential and the energy momentum distributions"

We point out a misleading treatment and incorrect expressions in a recent paper published in this Journal [Eur. Phys. J. C (2019) 79: 541] regarding solutions for the Dirac equation in presence of scalar and vector potentials in a class of flat Gödel-type space-time called Som-Raychaudhuri space-time. Following the appropriate procedure we obtain the solution for this system.

hep-th↗