Temperature-dependent spin susceptibility in a two-dimensional metal

Abstract

We consider a two-dimensional electron system with Coulomb interaction between particles at a finite temperature $T$. We show that the dynamic Kohn anomaly in the response function at $2{k}_{F}$ leads to a nonanalytic, linear-in-$T$ correction to the spin susceptibility, $\ensuremath{\delta}\ensuremath{\chi}(T)=aT$, the same as in systems with short-range interaction. We show that the singularity of the Coulomb interaction at $q=0$ does not invalidate the expansion of the prefactor $a$ in powers of ${r}_{s}$, but makes the expansion nonanalytic.