391 citations · 958 across the 29 of their papers we have counts for
29 papers
Two-dimensional heavy fermion in a monoatomic-layer Kondo lattice YbCu
Takuto Nakamura, Hiroki Sugihara, Yitong Chen +6
The Kondo effect between localized -electrons and conductive carriers leads to exotic physical phenomena. Among them, heavy-fermion (HF) systems, in which massive effective carr…
Growth of 2D topological material Bi on InSb(111)B with fractal surface structures
Yoshiyuki Ohtsubo, Takuto Nakamura, Shin-ichi Kimura
Bismuth (Bi) atomic layers are known as 2D topological materials with variety of the electronic structures and topological orders depending on the number of stacking layers. Recent…
Surface valence transition in SmS by alkali metal adsorption
Takuto Nakamura, Toru Nakaya, Yoshiyuki Ohtsubo +9
The electronic structure changes of SmS surfaces under potassium (K) doping are elucidated using synchrotron-based core-level photoelectron spectroscopy and angle-resolved photoele…
Breakdown of bulk-projected isotropy in surface electronic states of topological Kondo insulator SmB(001)
Yoshiyuki Ohtsubo, Toru Nakaya, Takuto Nakamura +4
The topology and spin-orbital polarization of two-dimensional (2D) surface electronic states have been extensively studied in this decade. One major interest in them is their close…
Fluctuated spin-orbital texture of Rashba-split surface states in real and reciprocal space
Takuto Nakamura, Yoshiyuki Ohtsubo, Ayumi Harasawa +4
Spin-orbit interaction (SOI) in low-dimensional systems, namely Rashba systems and the edge states of topological materials, is extensively studied in this decade as a promising so…
Optical study on electronic structure of the locally non-centrosymmetric CeRhAs
Shin-ichi Kimura, Jörg Sichelschmidt, Seunghyun Khim
The electronic structures of the heavy-fermion superconductor CeRhAs with the local inversion symmetry breaking and the reference material LaRhAs have been investig…
Bulk-Sensitive Spin-Resolved Resonant Electron Energy-Loss Spectroscopy (SR-rEELS): Observation of Element- and Spin-Selective Bulk Plasmons
Shin-ichi Kimura, Taishi Kawabata, Hiroki Matsumoto +8
We have developed a spin-resolved resonant electron energy-loss spectroscopy (SR-rEELS) in the primary energy of 0.3--1.5 keV, which corresponds to the core excitations of -$3d…
One-dimensionality of the spin-polarized surface conduction and valence bands of quasi-one-dimensional Bi chains on GaSb(110)-(21)
Yoshiyuki Ohtsubo, Naoki Tokumasu, Hiroshi Watanabe +8
Surface electronic structure and its one-dimensionality above and below the Fermi level () were surveyed on the Bi/GaSb(110)-(21) surface hosting quasi-one-dimen…
Fermi level tuning of one-dimensional giant Rashba system on a semiconductor substrate: Bi/GaSb(110)-(2x1)
Takuto Nakamura, Yoshiyuki Ohtsubo, Naoki Tokumasu +10
We fabricated spin-polarized surface electronic states with tunable Fermi level from semiconductor to low-dimensional metal in the Bi/GaSb(110)-(21) surface using angle-res…
Optical and photoelectrical studies on anisotropic metal-insulator transition of RuAs
Yuki Nakajima, Zenjiro Mita, Hiroshi Watanabe +6
The anisotropic changes in the electronic structure of a metal-to-insulator transition (MIT) material, RuAs, with two-step phase transition are reported by using polarized optical…
Temperature-driven modification of surface electronic structure on bismuth, a topological border material
Y. Ohtsubo, Y. Yamashita, J. Kishi +7
Single crystalline bismuth (Bi) is known to have a peculiar electronic structure which is very close to the topological phase transition. The modification of the surface states of…
Giant Rashba splitting of quasi-1D surface states on Bi/InAs(110)-(21)
T. Nakamura, Y. Ohtsubo, Y. Yamashita +10
Electronic states on the Bi/InAs(110)-(21) surface and its spin-polarized structure are revealed by angle-resolved photoelectron spectroscopy (ARPES), spin-resolved ARPES,…
Non-trivial surface states of samarium hexaboride at the (111) surface
Y. Ohtsubo, Y. Yamashita, K. Hagiwara +10
The peculiar metallic electronic states observed in the Kondo insulator, samarium hexaboride (SmB), has stimulated considerable attention among those studying non-trivial elect…
Direct observation of electron thermalization and electron-phonon coupling in photoexcited bismuth
J. Faure, J. Mauchain, E. Papalazarou +7
We investigate the ultrafast response of the bismuth (111) surface by means of time resolved photoemission spectroscopy. The direct visualization of the electronic structure allows…
Effects of finite-range interactions on the one-electron spectral properties of one-dimensional metals: Application to Bi/InSb(001)
J. M. P. Carmelo, T. Cadez, Y. Ohtsubo +2
We study the one-electron spectral properties of one-dimensional interacting electron systems in which the interactions have finite range. We employ a mobile quantum impurity schem…
Spin-polarized quasi 1D state with finite bandgap on the Bi/InSb(001) surface
J. Kishi, Y. Ohtsubo, T. Nakamura +13
One-dimensional (1D) electronic states were discovered on 1D surface atomic structure of Bi fabricated on semiconductor InSb(001) substrates by angle-resolved photoelectron spectro…
Topological surface states on Bi(111) based on empirical tight-binding calculations
Yoshiyuki Ohtsubo, Shin-ichi Kimura
The topological order of single-crystal Bi and its surface states on the (111) surface are studied in detail based on empirical tight-binding (TB) calculations. New TB parameters a…
Surface Kondo Effect and Non-Trivial Metallic State of the Kondo Insulator YbB12
Kenta Hagiwara, Yoshiyuki Ohtsubo, Masaharu Matsunami +13
A synergistic effect between strong electron correlation and spin-orbit interaction (SOI) has been theoretically predicted to result in a new topological state of quantum matter on…
Deviation from Fermi-liquid behavior in two-dimensional surface states of Au-induced nanowires on Ge(001) by correlation and localization
K. Yaji, R. Yukawa, S. Kim +7
The electronic states of Au-induced atomic nanowires on Ge(001) (Au/Ge(001) NWs) have been investigated by angle-resolved photoelectron spectroscopy with linearly polarized light.…
Spin-pumping into surface states of topological insulator α-Sn, spin to charge conversion at room temperature
J. -C. Rojas-Sánchez, S. Oyarzun, Y. Fu +12
We present experimental results on the conversion of a spin current into a charge current by spin pumping into the Dirac cone with helical spin polarization of the elemental topolo…
Topological phase diagram and saddle point singularity in a tunable topological crystalline insulator
Madhab Neupane, Su-Yang Xu, R. Sankar +17
We report the evolution of the surface electronic structure and surface material properties of a topological crystalline insulator (TCI) Pb1-xSnxSe as a function of various materia…
Hierarchical spin-orbital polarisation of a giant Rashba system
L. Bawden, J. M. Riley, C. H. Kim +15
The Rashba effect is one of the most striking manifestations of spin-orbit coupling in solids, and provides a cornerstone for the burgeoning field of semiconductor spintronics. It…
Tetragonal and collapsed-tetragonal phases of CaFe2As2 -- a view from angle-resolved photoemission and dynamical mean field theory
Ambroise van Roekeghem, Pierre Richard, Xun Shi +8
We present a study of the tetragonal to collapsed-tetragonal transition of CaFe2As2 using angle-resolved photoemission experiments and dynamical mean field theory-based electronic…
Surface Tomonaga-Luttinger liquid state on Bi/InSb(001)
Yoshiyuki Ohtsubo, Jun-ichiro Kishi, Kenta Hagiwara +8
A 1D metallic surface state was created on an anisotropic InSb(001) surface covered with Bi. Angle-resolved photoelectron spectroscopy (ARPES) showed a 1D Fermi contour with almost…