Non-Fermi liquids at finite temperature: Normal-state and infrared singularities

WANG, HUAJIA; TORROBA, GONZALO

Physical Review B

American Physical Society

Año: 2017 vol. 96

2469-9950

We analyze quantum criticality at finite temperature for a class of non-Fermi liquids with massless bosons. Finite temperature gives rise to new infrared singularities that invalidate standard perturbative treatments. We show how such divergences are resolved at a nonperturbative level, and obtain the resulting fermion self-energy. This leads to a new "thermal" non-Fermi liquid regime that extends over a wide range of frequencies, and which violates finite temperature scaling laws near quantum critical points. We analyze the resulting quantum critical region and properties of the retarded Green´s function. More generally, such effects dominate in the nearly static limit and are expected to have a nontrivial impact on superconductivity and transport.