Loop-current charge density wave driven by long-range Coulomb repulsion on the kagome lattice

Abstract

Recent experiments on vanadium-based nonmagnetic kagomé metals $A$V${}_3$Sb${}_5$ ($A=$ K, Rb, Cs) revealed evidence for possible spontaneous time-reversal symmetry (TRS) breaking in the charge density wave (CDW) ordered state. The long-sought-after quantum order of loop currents has been suggested as a candidate for the TRS breaking state. However, a microscopic model for the emergence of the loop-current CDW due to electronic correlations is still lacking. Here, we calculate the susceptibility of the real and imaginary bond orders on the kagomé lattice near van Hove filling, and reveal the importance of next-nearest-neighbor Coulomb repulsion $V_2$ in triggering the instability toward imaginary bond ordered CDW. The concrete effective single-orbital $t$-$V_1$-$V_2$ model on the kagomé lattice is then studied, where $t$ and $V_1$ are the hopping and Coulomb repulsion on the nearest-neighbor bonds. We obtain the mean-field ground states, analyze their properties, and determine the phase diagram in the plane spanned by $V_1$ and $V_2$ at van Hove filling. The region dominated by $V_1$ is occupied by a $2a_0\times 2a_0$ real CDW insulator with the inverse of Star-of-David (ISD) bond configuration. Increasing $V_2$ indeed drives a first-order transition from ISD to stabilized loop-current insulators that exhibit four possible current patterns of different topological properties, leading to orbital Chern insulators. We then extend these results away from van Hove filling and show that electron doping helps the stabilization of loop currents, and gives rise to doped orbital Chern insulators with emergent Chern Fermi pockets carrying large Berry curvature and orbital magnetic moment. Our findings provide a concrete model realization of the loop-current Chern metal at the mean-field level for the TRS breaking normal state of the kagomé superconductors.

12 pages, 7 figures

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• Electron-phonon coupling in the charge density wave state of CsV${}_3$Sb${}_5$
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• Loop currents in $A$V${}_3$Sb${}_5$ kagome metals: multipolar and toroidal magnetic orders
• Low-energy optical properties of the non-magnetic kagome metal CsV${}_3$Sb${}_5$
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• Multidome superconductivity in charge density wave kagome metals
• Statistical learning of engineered topological phases in the kagome superlattice of AV${}_3$Sb${}_5$
• Low-energy effective theory and symmetry classification of flux phases on Kagome lattice

Cited by in corpus (36)

• Quantum states and intertwining phases in kagome materials
• Chern Fermi pocket, topological pair density wave, and charge-4e and charge-6e superconductivity in kagome superconductors
• Charge-loop current order and Z3 nematicity mediated by bond-order fluctuations in kagome metal AV3Sb5 (A=Cs,Rb,K)
• Theory of nematic charge orders in kagome metals
• Intertwined van-Hove Singularities as a Mechanism for Loop Current Order in Kagome Metals
• The kagome Hubbard model from a functional renormalization group perspective
• Origin of $\pi$-shifted three-dimensional charge density waves in kagome metal AV${}_3$Sb${}_5$
• Probing orbital magnetism of a kagome metal CsV3Sb5 by a tuning fork resonator
• Emergent topological quantum orbits in the charge density wave phase of kagome metal CsV${}_3$Sb${}_5$
• Self-consistent theory of $2\times 2$ pair density waves in kagome superconductors
• Frustrated charge density wave and quasi-long-range bond-orientational order in the magnetic kagome FeGe
• Impact of the orbital current order on the superconducting properties of the kagome superconductors
• Electronic orders on the kagome lattice at the lower Van Hove filling
• Interplay between Chiral Charge Density Wave and Superconductivity in Kagome Superconductors: A Self-consistent Theoretical Analysis
• Exotic charge density waves and superconductivity on the Kagome Lattice
• Quantum-metric-induced giant and reversible nonreciprocal transport phenomena in chiral loop-current phases of kagome metals
• Electronic structure of $A$V${}_3$Sb${}_5$ kagome metals
• Superconductivity and pair density waves from nearest-neighbor interactions in frustrated lattice geometries
• Theories for charge-driven nematicity in kagome metals
• Photoemission Insights to Electronic Orders in Kagome Superconductor AV3Sb5
• Loop Current Order on the Kagome Lattice
• Inversion and Tunability of Van Hove Singularities in $A$V${}_3$Sb${}_5$ ($A$ = K, Rb, and Cs) kagome metals
• Interplay of Charge Density Wave and Magnetism on the Kagomé Lattice
• Impact of Charge Density Waves on Superconductivity and Topological Properties in AV${}_3$Sb${}_5$ Kagome Superconductors
• Josephson diodes induced by the loop current states
• Unveiling the nature of electronic transitions in RbV${}_3$Sb${}_5$ with Avoided Level Crossing $\mu$SR
• Loop-current order through the kagome looking glass
• Topological Aspects of Dirac Fermions in a Kagomé Lattice
• Inter-Layer Correlation of Loop Current Charge Density Wave on the Bilayer Kagomé Lattice
• Orbital altermagnetism on the kagome lattice and possible application to $A$V${}_3$Sb${}_5$
• Magnetism of kagome metals $\left({\text{Fe}}_{1-x}{\text{Co}}_x\right)\text{Sn}$ studied by $\mu$SR
• Current-induced magnetoresistance hysteresis in the kagome superconductor CsV${}_3$Sb${}_5$
• Role of On-site and Inter-site Coulomb Interactions in KV${}_3$Sb${}_5$: A first-principles DFT+$U$+$V$ study
• Microscopic origin of period-four stripe charge-density-wave in kagome metal CsV${}_3$Sb${}_5$
• Topological pair density waves in kagome superconductors
• Spontaneous emergence of altermagnetism in the single-orbital extended Hubbard model