New article published in Physical Review Letters by Prof. Gennady Gusev's group.
The article provides another contribution from the group to the study of electronic transport in two-dimensional Dirac systems..
In the article, we review the influence of electron-electron scattering on the resistivity of a two-dimensional system with a linear dispersion relation (Dirac type).
In conventional systems with a parabolic dispersion relation, where umklapp scattering is prohibited or ineffective due to the small Fermi surface, particle-particle scattering does not contribute to conductivity as it does not alter the total momentum.
However, within the framework of the Boltzmann kinetic model, we demonstrate that electron-electron scattering in Dirac systems can significantly contribute to conductivity, producing distinct temperature-dependent corrections: T4 behavior at low temperatures and T2 dependence at moderate temperatures.
Although the predicted T4 behavior is not observed experimentally—probably suppressed by dominant weak localization effects—T2 behavior is clearly confirmed by our experimental results.
Specifically, temperature-dependent resistivity data for a single-valley zero-gap HgTe quantum well exhibit T2 corrections, which align well with theoretical predictions.
Therefore, we challenge the paradigm that the T2 term in resistivity is absent in single-band two-dimensional metals.
Thus, we study theoretically and experimentally the T-dependent corrections to resistivity due to electron-electron interactions in systems with Dirac spectrum. These effects are absent in Galilean invariant systems with a parabolic spectrum. We believe that electronic transport phenomena are far from fully understood, and our research shows that transport dominated by electron-electron interactions is significantly influenced by material properties, including the shape of the Fermi surface and the dispersion relation.