Effective action and collective modes in quasi-one-dimensional spin-density-wave systems

Article

关键词: MAGNETIC-FIELD;    ELECTRIC-FIELD;    CHARGE;    DYNAMICS;    CONDUCTIVITY;    STATE;    PHASE;   

DOI  :  10.1103/PhysRevB.61.13493

来源: SCIE

【 摘 要 】

We derive the effective action describing the long-wavelength low-energy collective modes of quasi-one-dimensional spin-density-wave (SDW) systems, starting from the Hubbard model within a weak coupling approximation. The effective action for the spin-wave mode corresponds to an anisotropic nonlinear sigma model together with a Berry phase term. We compute the spin stiffness and the spin-wave velocity. We also obtain the effective action for the sliding mode (phason) taking into account the density fluctuations from the outset and in the presence of a weak external electromagnetic field. This leads to coupled equations for the phase of the SDW condensate and the charge-density fluctuations. We also calculate the conductivity and the density-density correlation function.

【 授权许可】

Free