Quantum critical response at the onset of spin-density-wave order in two-dimensional metals

Article

关键词: ELECTRICAL-CONDUCTIVITY;    INTERACTING FERMIONS;    NORMAL-STATE;    TEMPERATURE;    FLUCTUATIONS;    RESISTIVITY;    TRANSPORT;    MODEL;   

DOI  :  10.1103/PhysRevB.84.125115

来源: SCIE

【 摘 要 】

We study the frequency dependence of the electron self-energy and the optical conductivity in a recently developed field theory of the spin-density-wave quantum phase transition in two-dimensional metals. We focus on the interplay between the Fermi surface hot spots and the remainder of the cold Fermi surface. Scattering of electrons off the fluctuations of the spin-density-wave order parameter, phi, is strongest at the hot spots; we compute the conductivity due to this scattering in a rainbow approximation. We point out the importance of composite operators, built of products of the primary electron or phi fields: These have important effects also away from the hot spots. The simplest composite operator, phi(2), leads to deviations from Landau Fermi-liquid behavior on the entire Fermi surface. We also find an intermediate frequency window in which the cold electrons lose their quasiparticle form due to effectively one-dimensional scattering processes. The latter processes are part of umklapp scattering, which leads to singular contributions to the optical conductivity at the lowest frequencies at zero temperature.

【 授权许可】

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