Excitonic Phase Diagram of the Three-Chain Hubbard Model for Semiconducting and Semimetallic Ta${}_2$NiSe${}_5$

Abstract

Transition metal chalcogenide Ta${}_2$NiSe${}_5$, a promising material for the excitonic insulator, is investigated on the basis of the quasi-one-dimensional three-chain Hubbard model with two conduction ($c$) bands and one valence ($f$) band. In the semimetallic case where only one of two $c$ bands and the $f$ band cross the Fermi level, the transition from the $c$-$f$ compensated semimetal to the uniform excitonic insulator takes place at low temperature as the same as in the semiconducting case. On the other hand, when another $c$ band also crosses the Fermi level, the system shows three types of Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) excitonic orders characterized by the condensation of excitons with finite center-of-mass momentum $q$ corresponding to the three types of nesting vectors between the imbalanced two $c$ and one $f$ Fermi surfaces. The obtained FFLO states are metallic in contrast to the excitonic insulator and are expected to be observed in semimetallic Ta${}_2$NiSe${}_5$ under high pressure.

8 pages, 9 figures

References in corpus (12)

• Excitonic Bose-Einstein condensation in Ta2NiSe5 above room temperature
• On the possibility of an excitonic insulator at the semiconductor-semimetal transition
• Excitonic condensation in systems of strongly correlated electrons
• Giant exciton Fano resonance in quasi-one-dimensional Ta${}_2$NiSe${}_5$
• Effects of density imbalance on the BCS-BEC crossover in semiconductor electron-hole bilayers
• Bound state formation and nature of the excitonic insulator phase in the extended Falicov-Kimball model
• Microscopic quantum interference in excitonic condensation of Ta${}_2$NiSe${}_5$
• FFLO Excitonic State in the Three-Chain Hubbard Model for Ta${}_2$NiSe${}_5$
• Orbital diamagnetic susceptibility in excitonic condensation phase
• Excitonic Insulator State of the Extended Falicov-Kimball Model in the Cluster Dynamical Impurity Approximation
• Theory of Orbital Susceptibility on Excitonic Insulator
• First- and second-order phase transitions between the uniform and FFLO excitonic states in the three-chain Hubbard model for Ta2NiSe5

Cited by in corpus (7)

• Nature of symmetry breaking at the excitonic insulator transition: Ta${}_2$NiSe${}_5$
• Non-Coulomb strong electron-hole binding in $T{a}_{2}NiS{e}_5$ revealed by time- and angle-resolved photoemission spectroscopy
• Orthorhombic-to-monoclinic transition in Ta${}_2$NiSe${}_5$ due to a zone-center optical phonon instability
• Hybridization-gap Formation and Superconductivity in the Pressure-induced Semimetallic Phase of the Excitonic Insulator Ta${}_2$NiSe${}_5$
• A New Era of Excitonic Insulators
• Effects of Disorder on the Transport of Collective Modes in an Excitonic Condensate
• FFLO Superconductivity Mediated by Excitonic Fluctuation in Semimetallic Ta${}_2$NiSe${}_5$