Negative electron compressibility in the Hubbard Model

Abstract

Using the strong coupling diagram technique, we study the one-band repulsive Hubbard model on a two-dimensional square lattice in a wide range of chemical potentials $\mu$. Infinite sequences of diagrams describing interactions of electrons with spin and charge fluctuations are taken into account. At low temperatures, regions of the negative electron compressibility are found for $\mu <0$ and $\mu >U$, where $U$ is the Hubbard repulsion. For even lower temperatures, in the neighborhood of these regions, states with the phase separation are revealed.

11 pages, 5 figures

References in corpus (6)

• The electronic properties of graphene
• Absence of a Spin Liquid Phase in the Hubbard Model on the Honeycomb Lattice
• Momentum space anisotropy and pseudogaps: a comparative cluster dynamical mean field analysis of the doping-driven metal-insulator transition in the two dimensional Hubbard model
• Spectroscopic evidence for negative electronic compressibility in a quasi-three-dimensional spin-orbit correlated metal
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• The $t$-$t^{\prime }$-$t^{\prime \prime }$-$U$ Hubbard model and Fermi-level peak

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• Magnetic properties and superconductivity in the two-dimensional repulsive Hubbard model
• Low-frequency magnetic oscillations induced by strongly electron correlations
• Phonon-assisted phase separation in strongly correlated systems