Fractionally charged topological point defects on the kagome lattice

Abstract

We study a two-dimensional system of spin-polarized fermions on the kagome lattice at filling fraction f=1/3 interacting through a nearest-neighbor interaction V. Above a critical interaction strength V_c a charge-density wave with a broken Z_3 symmetry is stabilized. Using the unrestricted mean-field approximation, we present several arguments showing that elementary topological point defects in the order parameter bind a fractional charge. Our analysis makes use of two appealing properties of the model: (i) For weak interaction, the low-energy degrees of freedom are described by Dirac fermions coupled to a complex-valued mass field (order parameter). (ii) The nearest-neighbor interaction is geometrically frustrated at filling f=1/3. Both properties offer a route to fractionalization and yield a consistent value 1/2 for the fractional charge as long as the symmetry between the up and the down triangles of the kagome lattice is preserved. If this symmetry is violated, the value of the bound charge varies continuously with the strength of the symmetry-breaking term in the model. In addition, we have numerically computed the confining potential between two fractionally charged defects. We find that it grows linearly at large distances but can show a minimum at a finite separation for intermediate interactions. This indicates that the polaron state, formed upon doping the charge-density wave, can be viewed as a bound state of two defects.

12 pages, 12 figures

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Cited by in corpus (50)

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• Electronic Nature of Charge Density Wave and Electron-Phonon Coupling in Kagome Superconductor KV${}_3$Sb${}_5$
• Fermi surface mapping and the nature of charge density wave order in the kagome superconductor CsV${}_3$Sb${}_5$
• Charge density wave in kagome lattice intermetallic ScV6Sn6
• Highly-robust reentrant superconductivity in CsV3Sb5 under pressure
• Multiple Energy Scales and Anisotropic Energy Gap in the Charge-Density-Wave Phase of Kagome Superconductor CsV3Sb5
• Emergence of new van Hove singularities in the charge density wave state of a topological kagome metal RbV3Sb5
• Fermi level tuning and double-dome superconductivity in the kagome metals CsV${}_3$Sb${}_{5-x}$Sn${}_x$
• Topological Order and Semions in a Strongly Correlated Quantum Spin Hall Insulator
• Electronic correlations in the normal state of kagome superconductor KV${}_3$Sb${}_5$
• Competition between charge-density-wave and superconductivity in the kagome metal RbV3Sb5
• Anomalous Hall Effects of Light and Chiral Edge Modes on the Kagome Lattice
• Electronic structure of (LaNiO${}_3$)${}_2$/(LaAlO${}_3$)${}_N$ heterostructures grown along [111]
• Correlated Dirac Particles and Superconductivity on the Honeycomb Lattice
• Quantum Interactions in Topological R166 Kagome Magnet
• Cluster Mott insulators and two Curie-Weiss regimes on an anisotropic Kagome lattice
• Three-dimensional energy gap and origin of charge-density wave in kagome superconductor KV3Sb5
• Carrier Injection and Manipulation of Charge-Density Wave in Kagome Superconductor CsV3Sb5
• Evolution of highly anisotropic magnetism in the titanium-based kagome metals LnTi${}_3$Bi${}_4$ (Ln: La...Gd${}^{3+}$, Eu${}^{2+}$, Yb${}^{2+}$)
• Origin of Charge Density Wave in Layered Kagome Metal CsV${}_3$Sb${}_5$
• Boundary spin polarization as robust signature of topological phase transition in Majorana nanowires
• Emergent nematicity and intrinsic vs. extrinsic electronic scattering processes in the kagome metal CsV${}_3$Sb${}_5$
• Emergent orbitals in the cluster Mott insulator on a breathing Kagome lattice
• Fractional boundary charges in quantum dot arrays with density modulation
• Corner states of topological fullerenes
• Topological Insulators and Quantum Spin Liquids
• Novel three-dimensional Fermi surface and electron-correlation-induced charge density wave in FeGe
• Quantum phase transition and fractional excitations in a topological insulator thin film with Zeeman and excitonic masses
• Phase diagram of the 1/3-filled extended Hubbard model on the Kagome lattice
• Origin and stability of the charge density wave in ScV${}_6$Sn${}_6$
• Simulation and measurement of the fractional particle number in one-dimensional optical lattices
• Variational Monte Carlo Study of the 1/9 Magnetization Plateau in Kagome Antiferromagnets
• Anisotropic magnetism and band evolution induced by ferromagnetic phase transition in titanium-based kagome ferromagnet SmTi3Bi4
• Self-Trapped Polarons and Topological Defects in a Topological Mott Insulator
• YbV${}_3$Sb${}_4$ and EuV${}_3$Sb${}_4$, vanadium-based kagome metals with Yb${}^{2+}$ and Eu${}^{2+}$ zig-zag chains
• Particle number fractionalization of a one-dimensional atomic Fermi gas with synthetic spin-orbit coupling
• Order-by-disorder charge density wave condensation at $\text{q}=(\frac{1}{3},\frac{1}{3},\frac{1}{3})$ in kagome metal ScV${}_6$Sn${}_6$
• Clusterization transition between cluster Mott insulators on a breathing Kagomé lattice
• Interplay between Chiral Charge Density Wave and Superconductivity in Kagome Superconductors: A Self-consistent Theoretical Analysis
• Inhomogeneous magnetism in the doped kagome lattice of LaCuO2.66
• Quantum Oscillations Evidence for Topological Bands in Kagome Metal ScV6Sn6
• Symmetry-protected Dirac nodal lines and large spin Hall effect in ${\mathbf{V}}_6\mathbf{S}{\mathbf{b}}_4$ with kagome bilayer
• van Hove Singularity-Driven Emergence of Multiple Flat Bands in Kagome Superconductors
• Nature of the 1/3 Magnetization Plateau in Spin-1/2 Kagome Antiferromagnets
• Topological Aspects of Dirac Fermions in a Kagomé Lattice
• Role of On-site and Inter-site Coulomb Interactions in KV${}_3$Sb${}_5$: A first-principles DFT+$U$+$V$ study
• Charge-density waves in kagome-lattice extended Hubbard models at the van Hove filling