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arXiv · 1207.3212

Possible charge instabilities in two-dimensional doped Mott insulators

Matias Bejas·Andres Greco·Hiroyuki Yamase
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Abstract

Motivated by the growing evidence of the importance of charge fluctuations in the pseudogap phase in high-temperature cuprate superconductors, we apply a large-N expansion formulated in a path integral representation of the two-dimensional t-J model on a square lattice. We study all possible charge instabilities of the paramagnetic state in leading order of the 1/N expansion. While the d-wave charge density wave (flux phase) becomes the leading instability for various choices of model parameters, we find that a d-wave Pomeranchuk (electronic nematic phase) instability occurs as a next leading one. In particular, the nematic state has a strong tendency to become inhomogeneous. In the presence of a large second nearest-neighbor hopping integral, the flux phase is suppressed and the electronic nematic instability becomes leading in a high doping region. Besides these two major instabilities, bond-order phases occur as weaker instabilities close to half-filling. Phase separation is also detected in a finite temperature region near half-filling.

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Matias Bejas, Andres Greco, Hiroyuki Yamase. 2012-07-13. Possible charge instabilities in two-dimensional doped Mott insulators. https://doi.org/10.1103/physrevb.86.224509

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