arXiv subjects

A. Daria Dumitriu-I.

Publications and source records attributed to A. Daria Dumitriu-I..

4 recordsLinked to original sources

arXiv2026

Anomalous thermoelectric Hall response of interacting 2D Dirac fermions

We study the anomalous thermoelectric Hall response of two-dimensional massive Dirac fermions to first order in the electron-electron interaction. We compute both the Nernst response to a Luttinger-type gravitational potential and the particle magnetization, the latter being required to remove spurious non-transport contributions. We show that, for arbitrary interactions, the magnetization is described by a remarkably simple formula. Surprisingly, and contrary to expectations, subtracting the magnetization currents does not make the thermoelectric Hall coefficient vanish in the zero-temperature limit. We attribute this to violation of locality on the smallest length scales, which is inevitable in a quantized field theory, that happens to manifest itself in infrared physics.

cond-mat.mes-hall↗

arXiv2025

Broken Lorentz symmetry and violation of the Wiedemann-Franz law in topological insulators

We study a two-dimensional topological insulator in the presence of a static non-uniform gravitational field, which mimics the variations in the temperature distribution. We derive an effective boundary free energy functional for the gravitational field and show that, in contrast to the case of massive Dirac fermions, the addition of a Newtonian mass term significantly modifies the quantum anomalous behavior of the system. A non-zero bulk thermal current appears, which violates the Wiedemann-Franz law. The systematic approach we develop to calculate the contribution of edge states to thermal Hall conductivity and energy magnetization can easily be extended to other models.

cond-mat.mes-hall↗

arXiv2024

No bulk thermal currents in massive Dirac fermions

We calculate the energy current flowing in the bulk of a (2+1)-dimensional system of massive Dirac fermions and along a (1+1)-dimensional domain wall generated by flipping the sign of the particle mass. We show that, at low temperatures and in the long-wavelenghth limit, the system does not support a bulk thermal Hall current proportional to the temperature gradient. The only such contribution is due to states localised at the domain wall. This puts an end to a controversy existing in the literature and amends previous results obtained via first-order perturbation calculations.

cond-mat.mes-hall↗

arXiv2024

First-order effect of electron-electron interactions on the anomalous Hall conductivity of massive Dirac fermions

We investigate the first-order correction to the anomalous Hall conductivity of 2D massive Dirac fermions arising from electron-electron interactions. In a fully gapped system in the limit of zero temperature, we find that this correction vanishes, confirming the absence of perturbative corrections to the topological Hall conductivity. At finite temperature or chemical potential, we find that the total Hall response decays faster than in the non-interacting case, depending on the strength of electron-electron interactions. These features, which could potentially be observed experimentally, show the importance of two-body interactions for anomalous Hall transport.

cond-mat.mes-hall↗