We show that the singularities in the dynamical bosonic response functions of a two-dimensional Fermi liquid give rise to universal nonanalytic corrections to the results of the Fermi-liquid theory. In particular, we find a T2 term in the specific heat, linear-in-T terms in the effective mass and in the uniform spin susceptibility χs(Q=0,T), and |Q| term in χs(Q,T=0). The existence of these terms has been the subject of recent controversy, which is resolved in this paper. We present exact expressions for all nonanalytic terms to second order in a generic interaction U(Q) and show that the nonanalytic terms originate exclusively from forward- and backward-scattering of particles with zero total momentum.
Physical Review B
- Pub Date:
- March 2004
- Fermi-liquid theory and other phenomenological models;
- Fermions in reduced dimensions;
- Condensed Matter - Strongly Correlated Electrons
- references added, a typo corrected