Low energy electron-phonon eective action from symmetry analysis

D C CABRA; N E GRANDI; G A SILVA; M B STURLA

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2013 vol. B p. 45126 - 45141

1098-0121

Based on a detailed symmetry analysis, we state the general rules to build up the eective low energy eld theory describing a system of electrons weakly interacting with the lattice degrees of freedom. The basic elements in our construction are what we call the memory tensors", that keep track of the microscopic discrete symmetries into the coarse-grained action. The present approach can be applied to lattice systems in arbitrary dimensions and in a systematic way to any desired order in derivatives. We apply the method to the honeycomb lattice and re-obtain the by now well- known eective action of Dirac fermions coupled to ctitious gauge elds. As a second example, we derive the eective action for electrons in the kagome lattice, where our approach allows to obtainin a simple way the low energy electron-phonon coupling terms.