Showing 1–3 of 3 results for author: Kishi, J

Temperature-driven modification of surface electronic structure on bismuth, a topological border material

Authors: Y. Ohtsubo, Y. Yamashita, J. Kishi, S. Ideta, K. Tanaka, H. Yamane, J. E. Rault, P. Le Fèvre, F. Bertran, S. Kimura

Abstract: 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 Bi depending on the temperature are revealed by angle-resolved photoelectron spectroscopy (ARPES). At low temperature, the upper branch of the surface state merged to the projected bulk conduction bands around the… ▽ More 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 Bi depending on the temperature are revealed by angle-resolved photoelectron spectroscopy (ARPES). At low temperature, the upper branch of the surface state merged to the projected bulk conduction bands around the $\bar{M}$ point of the surface Brillouin zone (SBZ). In contrast, the same branch merged to the projected bulk valence bands at high temperature (400 K). Such behavior could be interpreted as a topological phase transition driven by the temperature, which might be applicable for future spin-thermoelectric devices. We discuss the possible mechanisms to cause such transition, such as the thermal lattice distortion and electron-phonon coupling. △ Less

Submitted 17 February, 2019; originally announced February 2019.

Comments: 15 pages with 6 figures (single column)

Journal ref: Journal of Physics D: Applied Physics 52 254002 (2019)

Spin-polarized quasi 1D state with finite bandgap on the Bi/InSb(001) surface

Authors: J. Kishi, Y. Ohtsubo, T. Nakamura, K. Yaji, A. Harasawa, F. Komori, S. Shin, J. E. Rault, P. Le Fèvre, F. Bertran, A. Taleb-Ibrahimi, M. Nurmamat, H. Yamane, S. Ideta, K. Tanaka, S. Kimura

Abstract: One-dimensional (1D) electronic states were discovered on 1D surface atomic structure of Bi fabricated on semiconductor InSb(001) substrates by angle-resolved photoelectron spectroscopy (ARPES). The 1D state showed steep, Dirac-cone-like dispersion along the 1D atomic structure with a finite direct bandgap opening as large as 150 meV. Moreover, spin-resolved ARPES revealed the spin polarization of… ▽ More One-dimensional (1D) electronic states were discovered on 1D surface atomic structure of Bi fabricated on semiconductor InSb(001) substrates by angle-resolved photoelectron spectroscopy (ARPES). The 1D state showed steep, Dirac-cone-like dispersion along the 1D atomic structure with a finite direct bandgap opening as large as 150 meV. Moreover, spin-resolved ARPES revealed the spin polarization of the 1D unoccupied states as well as that of the occupied states, the orientation of which inverted depending on the wave vector direction parallel to the 1D array on the surface. These results reveal that a spin-polarized quasi-1D carrier was realized on the surface of 1D Bi with highly efficient backscattering suppression, showing promise for use in future spintronic and energy-saving devices. △ Less

Submitted 16 October, 2017; v1 submitted 18 April, 2017; originally announced April 2017.

Comments: 9 pages (4 figures for the main text, 7 for supplemental material). To be published in Physical Review Materials (Copyright is transferred to APS)

Journal ref: Phys. Rev. Materials 1, 064602 (2017)

Surface Tomonaga-Luttinger liquid state on Bi/InSb(001)

Authors: Yoshiyuki Ohtsubo, Jun-ichiro Kishi, Kenta Hagiwara, Patrick Le Fèvre, François Bertran, Amina Taleb-Ibrahimi, Masaharu Matsunami, Hiroyuki Yamane, Shin-ichiro Ideta, Kiyohisa Tanaka, Shin-ichi Kimura

Abstract: 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 no 2D distortion. Close to the Fermi level ($E_{\rm F}$), the angle-integrated photoelectron spectra showed power-law scaling with the binding energy and temperature. The ARPES plot above $E_{\rm F}$ obtained thanks to… ▽ More 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 no 2D distortion. Close to the Fermi level ($E_{\rm F}$), the angle-integrated photoelectron spectra showed power-law scaling with the binding energy and temperature. The ARPES plot above $E_{\rm F}$ obtained thanks to thermally broadened Fermi edge at room temperature showed a 1D state with continuous metallic dispersion across $E_{\rm F}$ and power-law intensity suppression around $E_{\rm F}$. These results strongly suggest a Tomonaga-Luttinger liquid on the Bi/InSb(001) surface. △ Less

Submitted 20 November, 2015; v1 submitted 15 April, 2015; originally announced April 2015.

Comments: 12 pages (4 figures) for main text, 5 pages (6 figures) for supplemental material

Journal ref: Phys. Rev. Lett. 115, 256404 (2015)