Zero and Finite Temperature Phase Diagram of the Spinless Fermion Model in Infinite Dimensions

Abstract

The phase diagram of the model of spinless fermions with repulsive nearest neighbour interaction is calculated analytically on a hypercubic lattice in infinite dimensions $(d\to \infty )$. In spite of its simplicity the model displays a rich phase diagram depending on the doping $\delta$, the interaction $U$ and the temperature $T$. The system can be in the homogeneous phase (HOM), the nonsegregated AB charge density wave (AB-CDW), the AB phase separation region (PS-AB/HOM; coexistence of AB-CDW and HOM), the incommensurate phase (IP) or the IP phase separation region (PS-AB/IP; coexistence of AB-CDW and IP). We identify three important values of the interaction $U_{IPL}=0.572<U_{IPH}=1.914<U_{IP/PS}=4.212$ which distinguish four intervals of $U$. These imply four different types of phase diagrams. In all the three phase diagrams with $U$ below $U_{IP/PS}$ the IP appears. We propose a {\em new} general ansatz for the order parameter of this phase. A competition between the IP, the PS-AB/IP and the PS-AB/HOM is found. The relevance of our findings for the phase scenario of the Hubbard model is shown.

26 pages, latex, uuencoded compressed postscript files, 11 figures included; accepted by Annalen der Physik, Heidelberg; key words: incommensurate phases, CDW, infinite dimensions

References in corpus (5)

• Renormalization Group Approach to Interacting Fermions
• Indications of d_{x^2 - y^2} Superconductivity in the Two Dimensional t-J Model
• Transport Properties of the Infinite Dimensional Hubbard Model
• Magnetic phase diagram of the Hubbard model
• Existence of an incommensurate ground state of interacting spinless fermions in infinite dimensions

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• Conductivity in a symmetry broken phase: Spinless fermions with $1/d$ corrections
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• Monte Carlo study of fermionic trions in a square lattice with harmonic confinement
• Comment on "Robustness of a Local Fermi Liquid against Ferromagnetism and Phase Separation"
• Charge-Ordered States and the Phase Diagram of the Extended Hubbard Model on the Bethe lattice