ABSTRACT A topological insulator is an unusual quantum state of matter, characterized by the appearance, at its edges or on its surface, of a gapless metallic state that is protected by

time-reversal symmetry1,2. The discovery of topological insulators has stimulated the search for other topological states protected by other symmetries3,4,5,6,7, such as the recently

predicted8 topological crystalline insulator (TCI) in which the metallic surface states are protected by the mirror symmetry of the crystal. Here we present experimental evidence for the TCI

phase in tin telluride (SnTe), which has been predicted to be a TCI (ref. 9). Our angle-resolved photoemission spectra show the signature of a metallic Dirac-cone surface band, with its

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customer support SIMILAR CONTENT BEING VIEWED BY OTHERS GLIDE SYMMETRY PROTECTED HIGHER-ORDER TOPOLOGICAL INSULATORS FROM SEMIMETALS WITH BUTTERFLY-LIKE NODAL LINES Article Open access 13

December 2021 OBSERVATION OF TOPOLOGICAL SUPERCONDUCTIVITY IN A STOICHIOMETRIC TRANSITION METAL DICHALCOGENIDE 2M-WS2 Article Open access 17 May 2021 EMERGENT MYSTERY IN THE KONDO INSULATOR

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Fu for stimulating discussions. We also thank M. Komatsu, M. Nomura, E. Ieki, T. Takahashi, N. Inami, H. Kumigashira and K. Ono for their assistance in ARPES measurements, and T. Ueyama and

K. Eto for their assistance in crystal growth. This work was supported by JSPS (NEXT Program and KAKENHI 23224010), JST-CREST, MEXT of Japan (Innovative Area Topological Quantum Phenomena),

AFOSR (AOARD 124038) and KEK-PF (proposal number: 2012S2-001). AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Department of Physics, Tohoku University, Sendai 980-8578, Japan Y. Tanaka, T.

Sato, K. Nakayama & T. Takahashi * Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan Zhi Ren, Kouji Segawa & Yoichi Ando * WPI

Research Center, Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan S. Souma & T. Takahashi Authors * Y. Tanaka View author publications You can also

search for this author inPubMed Google Scholar * Zhi Ren View author publications You can also search for this author inPubMed Google Scholar * T. Sato View author publications You can also

search for this author inPubMed Google Scholar * K. Nakayama View author publications You can also search for this author inPubMed Google Scholar * S. Souma View author publications You can

also search for this author inPubMed Google Scholar * T. Takahashi View author publications You can also search for this author inPubMed Google Scholar * Kouji Segawa View author

publications You can also search for this author inPubMed Google Scholar * Yoichi Ando View author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS

Y.T., T.S., K.N., S.S. and T.T. performed ARPES measurements. Z.R., K.S. and Y.A. carried out the growth of the single crystals and their characterizations. Y.T., T.S. and Y.A. conceived the

experiments and wrote the manuscript. CORRESPONDING AUTHORS Correspondence to T. Sato or Yoichi Ando. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing financial

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Tanaka, Y., Ren, Z., Sato, T. _et al._ Experimental realization of a topological crystalline insulator in SnTe. _Nature Phys_ 8, 800–803 (2012). https://doi.org/10.1038/nphys2442 Download

citation * Received: 23 June 2012 * Accepted: 07 September 2012 * Published: 30 September 2012 * Issue Date: November 2012 * DOI: https://doi.org/10.1038/nphys2442 SHARE THIS ARTICLE Anyone

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