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arXiv · 1309.7839

Spin-polarized angle-resolved photoelectron spectroscopy of the so-predicted Kondo topological insulator SmB6

Shigemasa Suga·Kazuyuki Sakamoto·Taichi Okuda·Koji Miyamoto·Kenta Kuroda·Akira Sekiyama·Junichi Yamaguchi·Hidenori Fujiwara·Akinori Irizawa·Takahiro Ito·Shinichi Kimura·T. Balashov·W. Wulfhekel·S. Yeo·Fumitoshi Iga·Shin Imada
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Abstract

Undoped and slightly Eu-doped SmB6 show the opening of a gap with decreasing temperature below ~150 K. The spectral shapes near the Fermi level (EF) at 15 K have shown strong increase in intensity of a peak at a binding energy (EB) of around 12 meV with decreasing the photon energy (hn) from 17 eV down to 7 eV. Angle resolved spectra of SmB6 measured at hn = 35 eV just after the in-situ cleavage showed clear dispersions of several bands in the EB region from EF to 4 eV. Spin-polarized photoelectron spectra were then measured at 12 K and light incidence angle of ~50 deg. In contrast to the lack of spin polarization for the linearly polarized light excitation, clear spin polarization was observed in the case of circularly polarized light excitation. The two prominent peaks at EB~12 and ~150 meV have shown opposite signs of spin polarization which are reversed when the helicity of the light is reversed. The sign and the magnitude of spin- polarization are consistent with a theoretical prediction for the 6H5/2 and 6H7/2 states.

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Shigemasa Suga, Kazuyuki Sakamoto, Taichi Okuda, Koji Miyamoto, Kenta Kuroda, Akira Sekiyama, Junichi Yamaguchi, Hidenori Fujiwara, Akinori Irizawa, Takahiro Ito, Shinichi Kimura, T. Balashov, W. Wulfhekel, S. Yeo, Fumitoshi Iga, Shin Imada. 2013-09-30. Spin-polarized angle-resolved photoelectron spectroscopy of the so-predicted Kondo topological insulator SmB6. https://doi.org/10.7566/jpsj.83.014705

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