arXiv subjects

J. L. Acosta Avalo

Publications and source records attributed to J. L. Acosta Avalo.

4 recordsLinked to original sources

arXiv2026

Field-Induced Weyl-Like Crossings and Longitudinal Magnetoconductivity in Dirac Systems

We investigate the field-induced separation of effective Weyl-like crossings and the associated longitudinal magnetoconductivity in Dirac systems using a finite-temperature quantum electrodynamics response-function approach. Starting from the one-loop photon polarization tensor in a magnetized fermionic medium, we identify a longitudinal electromagnetic mode associated with a nonvanishing pseudoscalar invariant ${\bf E}\cdot{\bf B}$. We use this response to construct an effective low-energy Dirac model in which the two chiral sectors undergo opposite momentum shifts. Within this description, we derive an analytical expression for the longitudinal magnetoconductivity without introducing an independent phenomenological internode relaxation time. The chiral contribution contains an explicit $B^2$ prefactor, while its coefficient depends on the magnetic field and temperature through Landau-level thresholds and Fermi-Dirac occupation factors. The resulting conductivity exhibits a nonmonotonic magnetic-field dependence and an inverse-temperature regime under appropriate conditions. These results provide a connection, within the proposed effective model, between the longitudinal electromagnetic response, field-induced Weyl-like crossings, and longitudinal magnetotransport.

cond-mat.mes-hall↗

arXiv2026

Pair creation as a source of longitudinal chiral magnetoconductivity

We demonstrate that chiral transport in a strongly magnetized electron-positron plasma can arise dynamically from dissipative pair-creation processes encoded in the imaginary part of the photon polarization tensor within one-loop finite-temperature quantum electrodynamics (QED). In the kinematic region corresponding to longitudinal photon absorption, real electron-positron pair production induces axial charge nonconservation and generates an electric current parallel to the magnetic field, without requiring the introduction of an external chiral chemical potential. This provides a microscopic mechanism for chiral magnetic transport, offering an alternative to hydrodynamic or anomaly-based effective descriptions in which chirality imbalance is typically introduced as an external input. We derive an explicit expression for the longitudinal magnetoconductivity associated with this process and show that it exhibits an approximately quadratic dependence on the magnetic field only within a restricted intermediate regime. This behavior emerges from the dominance of the lowest Landau levels as a characteristic of negative longitudinal magnetoresistance. We further analyze how Pauli blocking regulates the pair-creation phase-space and demonstrate that the dynamically generated chiral imbalance is suppressed at high frequencies, revealing a transition between chiral-active and non-chiral-active regimes. Our results connect microscopic QED processes with anomaly-related transport phenomena in strongly magnetized relativistic plasmas, where pair creation provides a dynamical source for chiral imbalance.

hep-ph↗

arXiv2016

Chiral current generation in QED by longitudinal photons

We report the generation of a pseudovector electric current having imbalanced chirality in an electron-positron strongly magnetized gas in QED. It propagates along the external applied magnetic field B as a chiral magnetic effect in QED. It is triggered by a perturbative electric field parallel to B, associated to a pseudovector longitudinal mode propagating along B. An electromagnetic chemical potential was introduced, but our results remain valid even for vanishing chemical potential. A nonzero fermion mass was assumed, which is usually considered vanishing in the literature. In the quantum field theory formalism at finite temperature and density, an anomaly relation for the axial current was found for a medium of massive fermions. It bears some analogy to the Adler-Bell-Jackiw anomaly. From the expression for the chiral current in terms of the photon self-energy tensor in a medium, it is obtained that electrons and positrons scattered by longitudinal photons (inside the light cone) contribute to the chiral current, as well as the pair creation due to longitudinal photons (out of light cone). In the static limit, an electric pseudovector current is obtained in the lowest Landau level

hep-ph↗

arXiv2016

Chiral Magnetic Effect in QED induced by longitudinal photons

Chiral magnetic effect exists in an electron-positron strongly magnetized gas in QED. It is induced by an electric field parallel to the external field $\textbf{B}$, like that produced by the pseudovector longitudinal mode propagating along $\textbf{B}$. In the static limit, an electric pseudovector current is obtained in the lowest Landau level. We obtain a new axial anomaly expression in a medium of massive particles in the presence of $\textbf{B}$, for scattering or pair creation, similar to the usual QED axial anomaly. The effect is interesting in connection to the QCD chiral magnetic case reported in current literature.

hep-th↗