Evidence for topologically protected surface states and a superconducting phase in [Tl4](Tl(1-x)Sn(x))Te3 using photoemission, specific heat, and magnetization measurements, and density functional theory.
We report the discovery of surface states in the perovskite superconductor [Tl4]TlTe3 (Tl5Te3) and its nonsuperconducting tin-doped derivative [Tl4](Tl0.4Sn0.6)Te3 as observed by angle-resolved photoemission spectroscopy. Density functional theory calculations predict that the surface states are protected by a Z2 topology of the bulk band structure. Specific heat and magnetization measurements show that Tl5Te3 has a superconducting volume fraction in excess of 95%. Thus Tl5Te3 is an ideal material in which to study the interplay of bulk band topology and superconductivity.
Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Institute for Quantum Matter, Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
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KE
Arpino
Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Institute for Quantum Matter, Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
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DC
Wallace
Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA and Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA.
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YF
Nie
School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
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Birol
Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA and Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14853, USA.
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PD
King
Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.
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S
Chatterjee
Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.
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Uchida
Institute for Quantum Matter, Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
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SM
Koohpayeh
Institute for Quantum Matter, Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
J-J
JJ
Wen
Lujan Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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Page
School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
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CJ
Fennie
Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA and Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14853, USA.
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Shen
Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Institute for Quantum Matter, Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
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McQueen