%0 Book Section %1 statphys23_0070 %A Stariolo, D.A. %A Barci, D.G. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K competing group interactions nematic phases renormalization statphys23 systems topic-7 %T Competing Interactions, the Renormalization Group and the Isotropic-Nematic Phase Transition %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=70 %X We discuss $2D$ systems with Ising symmetry and competing interactions at different scales. In the framework of the Renormalization Group, we study the effect of relevant quartic interactions. In addition to the usual constant interaction term, we analyze the effect of quadrupole interactions in the self consistent Hartree approximation. We show that in the case of repulsive quadrupole interaction, there is a first order phase transition to a stripe phase in agreement with the well known Brazovskii result. However, in the case of attractive quadrupole interactions there is an isotropic-nematic second order transition with higher critical temperature. The temperature window for the existence of the intermediate nematic phase is calculated. Implications for experiments in systems like diblock copolymers and ferromagnetic ultrathin films are discussed.

@incollection{statphys23_0070, abstract = {We discuss $2D$ systems with Ising symmetry and competing interactions at different scales. In the framework of the Renormalization Group, we study the effect of relevant quartic interactions. In addition to the usual constant interaction term, we analyze the effect of quadrupole interactions in the self consistent Hartree approximation. We show that in the case of repulsive quadrupole interaction, there is a first order phase transition to a stripe phase in agreement with the well known Brazovskii result. However, in the case of attractive quadrupole interactions there is an isotropic-nematic second order transition with higher critical temperature. The temperature window for the existence of the intermediate nematic phase is calculated. Implications for experiments in systems like diblock copolymers and ferromagnetic ultrathin films are discussed.}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Stariolo, D.A. and Barci, D.G.}, biburl = {https://www.bibsonomy.org/bibtex/2713ab91b9a9c502d4e6af577f85bd16f/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {069805b03ccbcc48649924dc7e9b2579}, intrahash = {713ab91b9a9c502d4e6af577f85bd16f}, keywords = {competing group interactions nematic phases renormalization statphys23 systems topic-7}, month = {9-13 July}, timestamp = {2007-06-20T10:16:10.000+0200}, title = {Competing Interactions, the Renormalization Group and the Isotropic-Nematic Phase Transition}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=70}, year = 2007 }