arXiv subjects

Gabor Zala

Publications and source records attributed to Gabor Zala.

3 recordsLinked to original sources

arXiv2001

Interaction corrections at intermediate temperatures: magneto-resistance in parallel field

We consider the correction to conductivity of a 2D electron gas due to electron-electron interaction in the parallel magnetic field at arbitrary relation between temperature and the elastic mean free time. The correction exhibits non-trivial dependence on both temperature and the field. This dependence is determined by the Fermi liquid constant, which accounts for the spin-exchange interaction. In particular, the sign of the slope of the temperature dependence is not universal and can change with the increase of the field.

cond-mat.dis-nn↗

arXiv2001

Interaction corrections at intermediate temperatures: I. Longitudinal conductivity and kinetic equation

It is well known that electron-electron interaction in disordered systems leads to logarithmically divergent Altshuler-Aronov corrections to conductivity at low temperatures ($Tτ\ll 1$; $τ$ is the elastic mean-free time). This paper is devoted to the fate of such corrections at intermediate temperatures $Tτ\ge 1$. We show that in this (ballistic) regime the temperature dependence of conductivity is still governed by the same physical processes as the Altshuler-Aronov correction - scattering by Friedel oscillations. However, in this regime the correction is linear in temperature; the value and even the {\em sign} of the slope depends on the strength of electron-electron interaction. We show that the slope is directly related to the renormalization of the spin susceptibility and grows as the system approaches the ferromagnetic Stoner instability. Also, we obtain the temperature dependence of the conductivity in the cross-over region between the diffusive and the ballistic regimes. Finally, we derive the quantum kinetic equation, which describes electron transport for arbitrary value of $Tτ$.

cond-mat↗

arXiv2001

Interaction corrections to the Hall coefficient at intermediate temperatures

We investigate the effect of electron-electron interaction on the temperature dependence of the Hall coefficient of 2D electron gas at arbitrary relation between the temperature $T$ and the elastic mean-free time $τ$. At small temperature $Tτ\ll \hbar$ we reproduce the known relation between the logarithmic temperature dependences of the Hall coefficient and of the longitudinal conductivity. At higher temperatures, this relation is violated quite rapidly; correction to the Hall coefficient becomes $\propto 1/T$ whereas the longitudinal conductivity becomes linear in temperature.

cond-mat.dis-nn↗