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Bi2Te2Se ÌÚ×ÈdqXs\¢ÉÖ·é¤11) ðÐîÑXsÌÉa²ªòôIÉå·éªúÒ³êÄ¢·éBéB»Ì½ßC´áÁïdÍªÀ»Å«éXsgjNXfoCXÞ¿ÆµÄå«ÈúÒªñ¹çêÄ¢éB2.

Xspxªðõdqªõµ©µCÀÛÌ¨¿ÅÍCu\Ê»\¢ÌÎÌ«vªpxªðõdqªõiARPESjÍCªð\GlM[dq\¢¾¯ÅÍÈ­Xs\¢Éàe¿ð^¦é±ÆªªÍíðp¢ÄCõdqÌGlM[ÆúopxðªÍ·ª©ÁÄ«½BÜ½C±êÜÅ­©³ê½fBbNdq

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ç±ÌXspxªðõdqªõuÌJ­ðgíèCMott U  ð  p µ ½ Mott X s   o í15) â ­ ¥ « Ì^[Qbgðp·é±ÆÅ Mott XsoíÌ100{Ìø¦ðàÂá¬dqüñÜ^XsoíiVLEED XsoíjðJ­ÉüÇµÄ«½16) B{¤ÅÍCX
Fig. 1(Color online) (a) Spin current ow at surface state of 3
dimensional topological insulator (3D_TI) (b) Ideal Diraccone with helical spin texture on surface of 3D_TI. (c) Elas­tic scattering on ideal 3D_TI surface is shown. Here, spin
directions are denoted with arrows. (d) Elastic scattering on
Dirac cones with warping eect of C3V symmetry.

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110  úËõ March 2014 Vol.27 No.2(C) 2014 The Japanese Society for Synchrotron Radiation ResearchúËõj[X ¡ æ18ñú{úËõwï§ãÜóÜ¤ñ

Fig. 2 (Color online) (a), (b) Spin­resolved energy distribution curves for positive and negative emission angles along
the GS line excited with unpolarized He Ia light (hn21.2 eV). Spin­up and spin­down intensities are marked
with triangles pointing­up (red) and ­down (blue). (c) ARPES results obtained by p­polarized synchrotron radi­
ation light (hn22.5 eV). The contour plot is superimposed by triangles pointing­up and ­down indicating thespin character of the corresponding spectral features, as derived from spin­resolved spectra in Figs. 4(a) and 2(b). Here, the non spin­polarized peaks are denoted by squares (black). (d) Schematic E vs k// dispersion of S1and S.R. states without and with spin­selective hybridization.(e) Energy contours of the surface state S1 as func­tion of kx, ky for energies around the crossing point (ED) based on the parameters of the model calculation. (f)spin texture for the constant energy surface (solid line) at 20 meV above ED obtained from the model.

3.

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The spin characters obtained from spin resolved spectra inFig. 3(a). (c) Triangles pointing up (red) and down (blue)show experimental spin polarization for the upper and lower
parts of the TSS. Here, ky is measured from the G 2nd point.

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