Effective interactions in the stripe state of the two-dimensional Hubbard model

Institut fu¨r Physik, BTU Cottbus, PBox 101344, 03013 Cottbus, Germany(May 1, 2011)We investigate the structure of the pairing potential in the stripe phase of the two-dimensionalHubbard model. Based on the random phase approximation we discuss in detail the interactionsin the charge- and spin channel and compare our calculations with related considerations in com-mensurate antiferromagnets. Our main finding is that due to the incommensurate charge-densitywave formation the exchange of collective modes in the charge channel is significantly enhancedwith respect to the spin bag approach whereas due to the inhomogeneous charge distribution thecoupling to transverse spin fluctuations tends to be suppressed.I. INTRODUCTION