Antiferromagnetic State in $\kappa$-type Molecular Conductors: Spin Splitting and Mott Gap

Abstract

We numerically investigate the dynamical properties of $\kappa$-type molecular conductors in their antiferromagnetic Mott insulating state. By treating the extended Hubbard model on the two-dimensional $\kappa$-type lattice within the Lanzcos exact diagonalization method, we calculate the one-particle spectral function $A(\mathbf{k},\omega )$ and the optical absorption spectra taking advantage of twisted boundary conditions. We find spin splitting in $A(\mathbf{k},\omega )$ predicted by a previous Hartree-Fock study [M. Naka et al., Nat. Commun. 10, 4305 (2019)]; namely, their up- and down-spin components become different in the general $\mathbf{k}$-points of the Brillouin zone, even without the spin-orbit coupling. Furthermore, we demonstrate the variation in the optical properties near the Mott gap by the presence or absence of the antiferromagnetic order, tuned by a small staggered magnetic field.

5 pages, 3 figures, replaced by the published version

References in corpus (11)

• Unconventional critical behaviour in a quasi-two-dimensional organic conductor
• Perovskite as a spin current generator
• Anomalous Hall effect in $\kappa$-type organic antiferromagnets
• Asymmetry of the electronic states in hole- and electron-doped cuprates: Exact diagonalization study of the t-t'-t''-J model
• Bandwidth-controlled Mott transition in $\kappa -(BEDT-TTF{)}_{2}Cu[N(CN{)}_2]B{r}_{x}C{l}_{1-x}$ I. Optical studies of localized charge excitations
• Importance of Spin-Orbit Coupling in Organic BEDT-TTF and BEDT-TSF Salts
• Weakly spin-dependent band structures of antiferromagnetic perovskite LaMO${}_3$ (M = Cr, Mn, Fe)
• Electron-hole doping asymmetry of Fermi surface reconstructed in a simple Mott insulator
• Spectral properties near the Mott transition in the two-dimensional Hubbard model with next-nearest-neighbor hopping
• Phase Competition and Superconductivity in $\kappa$-(BEDT-TTF)${}_2$X: Importance of Intermolecular Coulomb Interactions
• Polar Charge Fluctuation and Superconductivity in Organic Conductor

Cited by in corpus (7)

• Fulde-Ferrell-Larkin-Ovchinnikov state induced by antiferromagnetic order in $\kappa$-type organic conductors
• Anomalous Hall effect in antiferromagnetic perovskites
• Spin Conductivity Based on Magnetic Toroidal Quadrupole Hidden in Antiferromagnets
• Magneto-optical spectra of an organic antiferromagnet as a candidate for an altermagnet
• Phase-modulated superconductivity via altermagnetism
• Correlated Zak insulator in organic antiferromagnets
• X-ray magnetic circular dichroism originating from the $T_z$ term in collinear altermagnets under trigonal crystal field