Interplay between Point-Group Symmetries and the Choice of the Bloch Basis in Multiband Models

Symmetry

Stefan A. Maier¹  Carsten Honerkamp¹ 

[1] Institute for Theoretical Solid State Physics, RWTH Aachen University, Aachen D-52056, Germany; E-Mail:

关键词: correlated electrons;    point-group symmetries;    functional renormalization group;   

DOI  :  10.3390/sym5040313

来源: mdpi

【 摘 要 】

We analyze the point-group symmetries of generic multiband tight-binding models with respect to the transformation properties of the effective interactions. While the vertex functions in the orbital language may transform non-trivially under point-group operations, their point-group behavior in the band language can be simplified by choosing a suitable Bloch basis. We first give two analytically accessible examples. Then, we show that, for a large class of models, a natural Bloch basis exists, in which the vertex functions in the band language transform trivially under all point-group operations. As a consequence, the point-group symmetries can be used to reduce the computational effort in perturbative many-particle approaches, such as the functional renormalization group.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.