Interplay of Pomeranchuk instability and superconductivity in the two-dimensional repulsive Hubbard model

Abstract

Interplay of Pomeranchuk instability (spontaneous symmetry breaking of the Fermi surface) and d-wave superconductivity is studied for the repulsive Hubbard model on the square lattice with the dynamical mean field theory combined with the fluctuation exchange approximation (FLEX+DMFT). We show that the four-fold symmetric Fermi surface becomes unstable against a spontaneous distortion into two-fold near the van Hove filling, where the symmetry of superconductivity coexisting with the Pomeranchuk distorted Fermi surface is modified from the d-wave pairing to (d+s)-wave. By systematically shifting the position of van Hove filling with varied second- and third-neighbor hoppings, we find that the transition temperature $T_{\mathrm{c}}^{\mathrm{PI}}$ of Pomeranchuk instability is more sensitively affected by the position of van Hove filling than the superconducting $T_{\mathrm{c}}^{\mathrm{SC}}$. This implies that the filling region for strong Pomeranchuk instability and that for strong superconducting fluctuations can be separated, and Pomeranchuk instability can appear even if the peak of $T_c^{\mathrm{PI}}$ is lower than the peak of $T_c^{\mathrm{SC}}$. An interesting observation is that the Fermi surface distortion can enhance the superconducting $T_{\mathrm{c}}^{\mathrm{SC}}$ in the overdoped regime, which is explained with a perturbation picture for small distortions.

8 pages, 5 figures

References in corpus (10)

• Continuous-time Monte Carlo methods for quantum impurity models
• The ALPS project release 1.3: open source software for strongly correlated systems
• Electronic liquid crystal state in the high-temperature superconductor YBCO(6.45)
• Dynamical vertex approximation - a step beyond dynamical mean field theory
• Connection between charge-density-wave order and charge transport in the cuprate superconductors
• Two-Orbital Model Explains the Higher Transition Temperature of the Single-Layer Hg-Cuprate Superconductor Compared to That of the La-Cuprate Superconductor
• Possible Quasi-One-Dimensional Fermi Surface in La_{2-x}Sr_{x}CuO_4
• On the dangers of partial diagrammatic summations: Benchmarks for the two-dimensional Hubbard model in the weak-coupling regime
• Magnetic excitations and their anisotropy in YBCO: slave-boson mean-field analysis of bilayer t-J model
• Competition of Fermi surface symmetry breaking and superconductivity