Condensed Matter Physics Seminar
2 p.m., Thursday, December 6
Room 1201, Physics Building
Interaction corrections to transport coefficients in twodimensional
electron gas at intermediate temperatures
Boris Narozhny
(Department of Physics, Brookhaven National Laboratory)
Abstract: It is well known that electronelectron interaction in
disordered systems leads to logarithmically divergent AltshulerAronov
corrections to conductivity at low temperatures ($T\tau\ll 1$; $\tau$ is the
elastic meanfree time). In this talk I discuss the fate of such corrections at
intermediate temperatures $T\tau\ge 1$. In that (ballistic) regime the
temperature dependence of conductivity is still governed by the same physical
processes as the AltshulerAronov correction  scattering by Friedel
oscillations. However, in that regime the correction is linear in temperature;
the value and even the {\em sign} of the slope depends on the strength of
electronelectron interaction. The slope is directly related to the
renormalization of the spin susceptibility and grows as the system approaches
the ferromagnetic Stoner instability. Also, I discuss the effect of
electronelectron interaction on the temperature dependence of the Hall
coefficient. At small temperature $T\tau \ll \hbar$ the known relation between
the logarithmic temperature dependences of the Hall coefficient and of the
longitudinal conductivity holds. At higher temperatures, this relation is
violated quite rapidly; the correction to the Hall coefficient becomes $\propto
1/T$ unlike the longitudinal conductivity which is linear in $T$.

Host: Sankar Das Sarma
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