TY - JOUR
T1 - Spin polarization of gapped dirac surface states near the topological phase transition in TlBi(S 1-xSe x) 2
AU - Souma, S.
AU - Komatsu, M.
AU - Nomura, M.
AU - Sato, T.
AU - Takayama, A.
AU - Takahashi, T.
AU - Eto, K.
AU - Segawa, Kouji
AU - Ando, Yoichi
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/11/2
Y1 - 2012/11/2
N2 - We performed systematic spin- and angle-resolved photoemission spectroscopy of TlBi(S 1-xSe x) 2 which undergoes a topological phase transition at x∼0.5. In TlBiSe 2 (x=1.0), we revealed a helical spin texture of Dirac-cone surface states with an intrinsic in-plane spin polarization of ∼0.8. The spin polarization still survives in the gapped surface states at x>0.5, although it gradually weakens upon approaching x=0.5 and vanishes in the nontopological phase. No evidence for the out-of-plane spin polarization was found, irrespective of x and momentum. The present results unambiguously indicate the topological origin of the gapped Dirac surface states, and also impose a constraint on models to explain the origin of mass acquisition of Dirac fermions.
AB - We performed systematic spin- and angle-resolved photoemission spectroscopy of TlBi(S 1-xSe x) 2 which undergoes a topological phase transition at x∼0.5. In TlBiSe 2 (x=1.0), we revealed a helical spin texture of Dirac-cone surface states with an intrinsic in-plane spin polarization of ∼0.8. The spin polarization still survives in the gapped surface states at x>0.5, although it gradually weakens upon approaching x=0.5 and vanishes in the nontopological phase. No evidence for the out-of-plane spin polarization was found, irrespective of x and momentum. The present results unambiguously indicate the topological origin of the gapped Dirac surface states, and also impose a constraint on models to explain the origin of mass acquisition of Dirac fermions.
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U2 - 10.1103/PhysRevLett.109.186804
DO - 10.1103/PhysRevLett.109.186804
M3 - Article
AN - SCOPUS:84868325991
VL - 109
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 18
M1 - 186804
ER -