Hole and electron dynamics in the triangular-lattice antiferromagnet -- interplay of frustration and spin fluctuations

Abstract

Single-particle dynamics in the 120${}^{\circ }$ ordered antiferromagnetic state of the triangular-lattice Hubbard model is studied using a physically transparent fluctuation approach in terms of multiple magnon emission and absorption processes within the noncrossing approximation. Hole and electron spectral features are evaluated at intermediate $U$, and analyzed in terms of a competition between the frustration-induced direct hopping and the virtual hopping terms. Finite $U$-induced competing interactions and frustration effects contributing through the magnon dispersion are also discussed. Finite contribution to self-energy correction from long-wavelength (Goldstone) modes, together with the high density of electron scattering states in the narrow, sharp peak in the upper band, result in strong fermion-magnon scattering leading to pronounced incoherent behaviour in the electron dynamics. The fluctuation-induced first-order metal-insulator transition due to vanishing band gap is also discussed.

10 pages, 13 figures

References in corpus (15)

• Spin Liquid State in an Organic Mott Insulator with Triangular Lattice
• Long range Neel order in the triangular Heisenberg model
• Similarities between organic and cuprate superconductors
• Nonmagnetic Insulating States near the Mott Transitions on Lattices with Geometrical Frustration and Implications for $\kappa$-(ET)${}_2$Cu${}_2(CN{)}_3$
• Magnetic Order and Spin Dynamics in Ferroelectric HoMnO${}_3$
• Indications of Unconventional Superconductivity in Doped and Undoped Triangular Antiferromagnets
• Transport criticality of the first-order Mott transition in a quasi-two-dimensional organic conductor, $\kappa$-(BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Cl
• Quasi two-dimensional antiferromagnet on a triangular lattice RbFe(MoO4)2
• Magnetic-Field-Induced Mott Transition in a Quasi-Two-Dimensional Organic Conductor
• Quasiparticle vanishing driven by geometrical frustration
• Finite-$U$ induced competing interactions, frustration, and quantum phase transition in a triangular-lattice antiferromagnet
• Spin-wave spectrum in La2CuO4 -- double occupancy and competing interaction effects
• Spin polarons in triangular antiferromagnets
• Effective Hamiltonians for holes in antiferromagnets: a new approach to implement forbidden double occupancy
• Self-energy corrections in an antiferromagnet -- interplay of classical and quantum effects on quasiparticle dispersion

Cited by in corpus (6)

• Dynamical mean field study of the Mott transition in the half-filled Hubbard model on a triangular lattice
• Holes and magnetic polarons in a triangular lattice antiferromagnet
• Proposal for asymmetric photoemission and tunneling spectroscopies in quantum simulators of the triangular-lattice Fermi-Hubbard model
• Spin waves in a band ferromagnet: spin-rotationally symmetric study with self-energy and vertex corrections
• Spin waves in the AF state of the $t$-$t^{\prime }$ Hubbard model on the fcc lattice: competing interactions, frustration, and instabilities
• Correlation effects on magnetic frustration in the triangular-lattice Hubbard model