191 citations · 1.4k across the 36 of their papers we have counts for
36 papers
A New Era of Excitonic Insulators
Tatsuya Kaneko, Yukinori Ohta
The fundamental idea of the excitonic insulator (EI) driven by electron-hole correlations in narrow-gap semiconductors or semimetals was originally proposed in the 1960s, and only…
Exciton-spin interactions in antiferromagnetic charge-transfer insulators
Tatsuya Kaneko, Yuta Murakami, Denis Golež +2
We derive exciton-spin interactions from a microscopic correlated model that captures important aspects of the physics of charge-transfer (CT) insulators to address magnetism assoc…
Wannier-Stark ladders and Stark shifts of excitons in Mott insulators
Mina Udono, Tatsuya Kaneko, Koudai Sugimoto
External-field driven energy-level discretization, such as Landau quantization or Stark localization, is one of the most intriguing phenomena in quantum systems. We investigate the…
Spin, charge and -spin separation in one-dimensional photo-doped Mott insulators
Yuta Murakami, Shintaro Takayoshi, Tatsuya Kaneko +2
We show that effectively cold metastable states in one-dimensional photo-doped Mott insulators described by the extended Hubbard model exhibit spin, charge and -spin separation.…
Excitonic effects on high-harmonic generation in Mott insulators
Mina Udono, Koudai Sugimoto, Tatsuya Kaneko +1
To study excitonic effects on high-harmonic generation (HHG) in Mott insulators, we investigate pumped nonequilibrium dynamics in the one-dimensional extended Hubbard model. By emp…
Second-order magnetic responses in quantum magnets: Magnetization under ac magnetic fields
Tatsuya Kaneko, Yuta Murakami, Shintaro Takayoshi +1
We investigate second-order magnetic responses of quantum magnets against ac magnetic fields. We focus on the case where the component of the spin is conserved in the unperturb…
Third-harmonic generation in excitonic insulators
Tetsuhiro Tanabe, Tatsuya Kaneko, Yukinori Ohta
We study third-harmonic generation (THG) in an excitonic insulator (EI) described in a two-band correlated electron model. Employing the perturbative expansion with respect to the…
Hybridization-gap Formation and Superconductivity in the Pressure-induced Semimetallic Phase of the Excitonic Insulator TaNiSe
Kazuyuki Matsubayashi, Hidekazu Okamura, Takashi Mizokawa +19
The excitonic insulator TaNiSe experiences a first-order structural transition under pressure from rippled to flat layer-structure at Ps = 3 GPa, which drives the system fr…
Exploring nonequilibrium phases of photo-doped Mott insulators with Generalized Gibbs ensembles
Yuta Murakami, Shintaro Takayoshi, Tatsuya Kaneko +4
Photo-excited strongly correlated systems can exhibit intriguing non-thermal phases, but the theoretical investigation of them poses significant challenges. In this work, we introd…
Second order Josephson effect in excitonic insulators
Zhiyuan Sun, Tatsuya Kaneko, Denis Golež +1
We show that in electron-hole bilayers with excitonic order arising from conduction and valence bands formed by atomic orbitals that have different parities, nonzero interlayer tun…
Bulk Photovoltaic Effect Driven by Collective Excitations in a Correlated Insulator
Tatsuya Kaneko, Zhiyuan Sun, Yuta Murakami +2
We investigate the bulk photovoltaic effect, which rectifies light into electric current, in a collective quantum state with correlation driven electronic ferroelectricity. We show…
Photoinduced -pairing at finite temperatures
Satoshi Ejima, Tatsuya Kaneko, Florian Lange +2
We numerically prove photoinduced -pairing in a half-filled fermionic Hubbard chain at both zero and finite temperature. The result, obtained by combining the matrix-product-sta…
Collective Modes in Excitonic Insulators: Effects of Electron-Phonon Coupling and Signatures in Optical Response
Yuta Murakami, Denis Golež, Tatsuya Kaneko +3
We consider a two-band spinless model describing an excitonic insulator (EI) on the two-dimensional square lattice with anisotropic hopping parameters and electron-phonon (el-ph) c…
Photoinduced -pairing in One-dimensional Mott Insulators
Satoshi Ejima, Tatsuya Kaneko, Florian Lange +2
Employing the density-matrix renormalization group technique in the matrix-product-state representation, we investigate the photoexcited superconducting correlations induced by the…
Superconductivity and charge density wave under a time-dependent periodic field in the one-dimensional attractive Hubbard model
Ryo Fujiuchi, Tatsuya Kaneko, Koudai Sugimoto +2
We investigate the competition between superconductivity (SC) and charge density wave (CDW) under a time-dependent periodic field in the attractive Hubbard model. By employing the…
Charge stiffness and long-range correlation in the optically induced -pairing state of the one-dimensional Hubbard model
Tatsuya Kaneko, Seiji Yunoki, Andrew J. Millis
We show that optical excitation of the Mott insulating phase of the one-dimensional Hubbard model can create a state possessing two of the hallmarks of superconductivity: a nonvani…
Photoinduced electron-electron pairing in the extended Falicov-Kimball model
Ryo Fujiuchi, Tatsuya Kaneko, Yukinori Ohta +1
By employing the time-dependent exact diagonalization method, we investigate the photoexcited states of the excitonic insulator in the extended Falicov-Kimball model (EFKM). We her…
Spin texture and spin current in excitonic phases of the two-band Hubbard model
Hisao Nishida, Shohei Miyakoshi, Tatsuya Kaneko +2
Using the mean-field approximation, we study the -space spin textures and local spin currents emerged in the spin-triplet excitonic insulator states of the two-band Hubbard mode…
Photoinduced Pairing in the Hubbard Model
Tatsuya Kaneko, Tomonori Shirakawa, Sandro Sorella +1
By employing unbiased numerical methods, we show that pulse irradiation can induce unconventional superconductivity even in the Mott insulator of the Hubbard model. The superconduc…
Strong Coupling Nature of the Excitonic Insulator State in TaNiSe
K. Sugimoto, S. Nishimoto, T. Kaneko +1
We analyze the measured optical conductivity spectra using the density-functional-theory-based electronic structure calculation and density-matrix renormalization group calculation…
Exciton-phonon cooperative mechanism of the triple- charge-density-wave and antiferroelectric electron polarization in TiSe
Tatsuya Kaneko, Yukinori Ohta, Seiji Yunoki
We investigate the microscopic mechanisms of the charge-density-wave (CDW) formation in a monolayer TiSe using a realistic multiorbital - model with electron-phonon coupl…
Excitonic Insulator State of the Extended Falicov-Kimball Model in the Cluster Dynamical Impurity Approximation
Kosuke Hamada, Tatsuya Kaneko, Shohei Miyakoshi +1
We comparatively study the excitonic insulator state in the extended Falicov-Kimball model (EFKM, a spinless two-band model) on the two-dimensional square lattice using the variati…
Mott transition and magnetism of the triangular-lattice Hubbard model with next-nearest-neighbor hopping
Kazuma Misumi, Tatsuya Kaneko, Yukinori Ohta
The variational cluster approximation is used to study the isotropic triangular-lattice Hubbard model at half filling, taking into account the nearest-neighbor () and next-nea…
Electric and magnetic multipoles and bond orders in excitonic insulators
Tatsuya Kaneko, Yukinori Ohta
We study the charge and spin density distributions of excitonic insulator (EI) states in the tight-binding approximation. We first discuss the charge and spin densities of the EI s…