285 citations · 2.6k across the 51 of their papers we have counts for
50 papers
Correlated topological-polarization surface states in the narrow-gap insulator FeSb2
Takahiro Iwagaki, Hideki Matsuoka, Ginta Hoshino +7
Strong electron correlations and band topology each generate rich quantum phases, but conflicting elemental requirements have largely kept them apart. Topological polarization offe…
Carrier-density dependence of magnetotransport in correlated Dirac semimetal CaIrO
Rinsuke Yamada, Jun Fujioka, Minoru Kawamura +8
We report the carrier density dependence of the magnetotransport property in the correlated Dirac semimetal CaIrO. In the dilute carrier density region ( $\sim 2.2 \…
Unraveling a chemical-bond-driven root of topology in three-dimensional chiral crystals
Shungo Aoyagi, Shunsuke Kitou, Yuiga Nakamura +6
Chirality manifests across multiple scales, yielding unique phenomena that break mirror symmetry. In chiral materials, unexpectedly large spin-filtering or photogalvanic effects ha…
Designing single and degenerate flat bands in the kagome lattice with long-range hopping
Yuta Taguchi, Motoaki Hirayama, Takashi Miyake
We investigate the electronic structure of the kagome lattice model with first, second, and two kinds of third nearest-neighbor hoppings. We reveal that by tuning the third nearest…
Spontaneous topological Hall effect induced by non-coplanar antiferromagnetic order in intercalated van der Waals materials
H. Takagi, R. Takagi, S. Minami +14
In ferromagnets, electric current generally induces transverse Hall voltage in proportion to magnetization (anomalous Hall effect), and it is frequently used for electrical readout…
Crystal-symmetry-protected gapless vortex-line phases in superconducting Dirac semimetals
Shingo Kobayashi, Shuntaro Sumita, Motoaki Hirayama +1
Vortex lines in superconducting Dirac semimetals realize crystal-symmetry-protected gapless vortex-line phases in which gapless excitations propagate inside a vortex line, in the p…
Topological invariant and domain connectivity in moiré materials
Ikuma Tateishi, Motoaki Hirayama
Recently, a moiré material has been proposed in which multiple domains of different topological phases appear in the moiré unit cell due to a large moiré modulation. Topological pr…
Signature of topological band crossing in ferromagnetic Cr1/3NbSe2 epitaxial thin film
Bruno Kenichi Saika, Satoshi Hamao, Yuki Majima +14
In intercalated transition metal dichalcogenides (I-TMDC), transition metal intercalation introduces magnetic phases which in some cases induce topological band crossing. However,…
material design of Ag-based oxides for high- superconductor
Motoaki Hirayama, Michael Thobias Schmid, Terumasa Tadano +2
We propose silver-based oxides with layered perovskite structure as candidates of exhibiting intriguing feature of strongly correlated electrons. The compounds show unique covalenc…
Efficient hydrogen evolution reaction due to topological polarization
Ming-Chun Jiang, Guang-Yu Guo, Motoaki Hirayama +3
Materials carrying topological surface states (TSS) provide a fascinating platform for the hydrogen evolution reaction (HER). Based on systematic first-principles calculations for…
low-energy effective Hamiltonians for high-temperature superconducting cuprates BiSrCuO, BiSrCaCuO, HgBaCuO and CaCuO
Jean-Baptiste Morée, Motoaki Hirayama, Michael Thobias Schmid +2
We derive low-energy effective Hamiltonians (LEH) for high-temperature superconducting (SC) copper oxides BiSrCuO (Bi2201, , $T_c^{\rm exp} \s…
Materials Design of Superconductivity in Nickelates
Motoharu Kitatani, Yusuke Nomura, Motoaki Hirayama +1
Motivated by the recent theoretical materials design of superconducting nickelates for which the charge transfer from the NiO to the block layer is completely suppressed…
downfolding based on the GW approximation for infinite-layer nickelates
Motoaki Hirayama, Yusuke Nomura, Ryotaro Arita
We derive an effective three-orbital model for the infinite-layer nickelates based on the band structure obtained by the GW approximation (GWA), where we consider the Ni 3$d_{x^2-y…
Interstitial-Electron-Induced Topological Molecular Crystals
Tonghua Yu, Ryotaro Arita, Motoaki Hirayama
Topological phases usually are unreachable in molecular solids, which are characteristic of weakly dispersed energy bands with a large gap, in contrast to topological materials. In…
Tuning the Parity Mixing of Singlet-Septet Pairing in a Half-Heusler Superconductor
K. Ishihara, T. Takenaka, Y. Miao +12
In superconductors, electrons with spin form Cooper pairs whose spin structure is usually singlet () or triplet (). When the electronic structure near the F…
Quantum spin Hall effect from multi-scale band inversion in twisted bilayer Bi(TeSe)
Ikuma Tateishi, Motoaki Hirayama
Moiré materials have become one of the most active fields in material science in recent years due to their high tunability, and their unique properties emerge from the Moiré-scale…
Field-induced multiple metal-insulator crossovers of correlated Dirac electrons of perovskite CaIrO
R. Yamada, J. Fujioka, M. Kawamura +10
The interplay between electron correlation and topology of relativistic electrons may lead to a new stage of the research on quantum materials and emergent functions. The emergence…
Anisotropic superconductivity in topological crystalline metal PbTaS with multiple Dirac fermions
Xiaohui Yang, Tonghua Yu, Chenchao Xu +10
Topological crystalline metals/semimetals (TCMs) have stimulated a great research interest, which broaden the classification of topological phases and provide a valuable platform t…
Emergence of spin-orbit coupled ferromagnetic surface state derived from Zak phase in a nonmagnetic insulator FeSi
Yusuke Ohtsuka, Naoya Kanazawa, Motoaki Hirayama +13
A chiral compound FeSi is a nonmagnetic narrow-gap insulator, exhibiting peculiar charge and spin dynamics beyond a simple band-structure picture. Those unusual features have been…
Quantum transport observed in films of magnetic topological semimetal EuSb
Mizuki Ohno, Masaki Uchida, Ryosuke Kurihara +10
We report fabrication of EuSb single-crystalline films and investigation of their quantum transport. First-principles calculations demonstrate that EuSb is a magnetic topol…
Absence of conventional room temperature superconductivity at high pressure in carbon doped HS
Tianchun Wang, Motoaki Hirayama, Takuya Nomoto +3
In this work, we show that the same theoretical tools that successfully explain other hydrides systems under pressure seem to be at odds with the recently claimed conventional room…
Multipole representation for anisotropic Coulomb interactions
Shoma Iimura, Motoaki Hirayama, Shintaro Hoshino
Multipole representation is proposed for the anisotropic Coulomb interactions in solids. Any local interactions can be expressed as the product of two multipole operators, and the…
First-Principles Design of Halide-Reduced Electrides: Magnetism and Topological Phases
Tonghua Yu, Motoaki Hirayama, José A. Flores-Livas +3
We propose a design scheme for potential electrides derived from conventional materials. Starting with rare-earth-based ternary halides, we exclude halogens and perform global stru…
Enhancement of transverse thermoelectric conductivity originating from stationary points in nodal line
Susumu Minami, Fumiyuki Ishii, Motoaki Hirayama +3
Motivated by the recent discovery of a large anomalous Nernst effect in CoMnGa, Fe (=Al, Ga) and CoSnS, we performed a first-principles study to clarify the…