Spin exchange and superconductivity in a $t-J^{\prime }-V$ model for two-dimensional quarter-filled systems

Abstract

The effect of antiferromagnetic spin fluctuations on two-dimensional quarter-filled systems is studied theoretically. An effective $t-J^{\prime }-V$ model on a square lattice which accounts for checkerboard charge fluctuations and next-nearest-neighbors antiferromagnetic spin fluctuations is considered. From calculations based on large-N theory on this model it is found that the exchange interaction, $J^{\prime }$, increases the attraction between electrons in the d${}_{xy}$ channel only, so that both charge and spin fluctuations work cooperatively to produce d${}_{xy}$ pairing.

9 pages, 6 figures