Understanding competing instabilities in systems with correlated fermions remains one of the holy grails of modern condensed matter physics. Among the fermionic lattice models used to this effect, the extended Hubbard model occupies a prime place due to the potential relevance of its repulsive and attractive versions for both electronic materials and artificial systems. Using the recently introduced multichannel fluctuating field approach, we address the interplay of fluctuations in the charge density wave, $s$ -wave superconducting, and phase separation channels in the attractive extended Hubbard model. Despite the fact that this model has been intensively studied for decades, our approach allows us to identify a phase that has not been analyzed before and which is characterized by the coexistence of collective $s$ -wave superconducting and phase separation fluctuations. Our findings resonate with previous observations of interplaying phase separation and superconducting phases in electronic systems, most importantly in high-temperature superconductors.Understanding competing instabilities in systems with correlated fermions remains one of the holy grails of modern condensed matter physics. Among the fermionic lattice models used to this effect, the extended Hubbard model occupies a prime place due to the potential relevance of its repulsive and attractive versions for both electronic materials and artificial systems. Using the recently introduced multichannel fluctuating field approach, we address the interplay of fluctuations in the charge density wave, $s$-wave superconducting, and phase separation channels in the attractive extended Hubbard model. Despite the fact that this model has been intensively studied for decades, our approach allows us to identify a phase that has not been analyzed before and which is characterized by the coexistence of collective $s$-wave superconducting and phase separation fluctuations. Our findings resonate with previous observations of interplaying phase separation and superconducting phases in electronic systems, most importantly in high-temperature superconductors.

arXiv:2301.10755Physical review. B./Physical review. BNov 29, 20236 citations

The Phase Diagram of the One-Dimensional Extended Hubbard Model

H. Q. Lin, Eduardo R. Gagliano, David K Campbell +2 more

NATO ASI series. Series B : PhysicsJan 1, 19956 citations

Electron Phase Separations Involving Superconductivity in the Extended Hubbard Models with Pair Hopping Interaction

Konrad Jerzy Kapcia

In this work the extended Hubbard models with pair hopping interaction (at the atomic limit) are investigated within the variational approach, which treats the on-site interaction term exactly and the intersite interactions within the mean-eld approximation (exact in d → +∞).We analyze mutual stability of the superconducting phase and charge or (ferro/antiferro-)magnetic orderings as well as homogeneous mixed phases.Our preliminary results for U = 0 show that the superconducting phase can coexist with the charge or (ferro/antiferro-)magnetic phases only in states with electron phase separation.In this work the extended Hubbard models with pair hopping interaction (at the atomic limit) are investigated within the variational approach, which treats the on-site interaction term exactly and the intersite interactions within the mean-eld approximation (exact in d → +∞).We analyze mutual stability of the superconducting phase and charge or (ferro/antiferro-)magnetic orderings as well as homogeneous mixed phases.Our preliminary results for U = 0 show that the superconducting phase can coexist with the charge or (ferro/antiferro-)magnetic phases only in states with electron phase separation.

Acta Physica Polonica AFeb 1, 201511 citations

On the phase diagram of the Extended Hubbard Model

Janusz Jędrzejewski

The European Physical Journal BSep 1, 198513 citations

s

-wave superconducting, and phase separation channels in the attractive extended Hubbard model. Despite the fact that this model has been intensively studied for decades, our approach allows us to identify a phase that has not been analyzed before and which is characterized by the coexistence of collective

s

-wave superconducting and phase separation fluctuations. Our findings resonate with previous observations of interplaying phase separation and superconducting phases in electronic systems, most importantly in high-temperature superconductors.