title: Topological Quantum Phase Transition and Superconductivity Induced by Pressure in the Bismuth Tellurohalide BiTeI.
abstract: A pressure-induced topological quantum phase transition has been theoretically predicted for the semiconductor bismuth tellurohalide BiTeI with giant Rashba spin splitting. In this work, evolution of the electrical transport properties in BiTeI and BiTeBr is investigated under high pressure. The pressure-dependent resistivity in a wide temperature range passes through a minimum at around 3 GPa, indicating the predicted topological quantum phase transition in BiTeI. Superconductivity is observed in both BiTeI and BiTeBr, while resistivity at higher temperatures still exhibits semiconducting behavior. Theoretical calculations suggest that superconductivity may develop from the multivalley semiconductor phase. The superconducting transition temperature, Tc, increases with applied pressure and reaches a maximum value of 5.2 K at 23.5 GPa for BiTeI (4.8 K at 31.7 GPa for BiTeBr), followed by a slow decrease. The results demonstrate that BiTeX (X = I, Br) compounds with nontrivial topology of electronic states display new ground states upon compression.
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany.
authors.forename: Yanpeng
authors.initials: Y
authors.lastname: Qi
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany.|School of Physical Science and Technology, ShanghaiTech University, Shanghai, 200031, China.
authors.forename: Wujun
authors.initials: W
authors.lastname: Shi
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany.|Shubnikov Institute of Crystallography of Federal Scientific Research Centre "Crystallography and Photonics", Russian Academy of Sciences, Moscow, 119333, Russia.
authors.forename: Pavel G
authors.initials: PG
authors.lastname: Naumov
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany.
authors.forename: Nitesh
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Institute of Physics, Academia Sinica, Taipei, 10617, Taiwan.|Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Raman
authors.initials: R
authors.lastname: Sankar
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Schnelle
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany.
authors.forename: Chandra
authors.initials: C
authors.lastname: Shekhar
authors.affiliation: Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Fang-Cheng
authors.initials: FC
authors.lastname: Chou
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Felser
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany.|School of Physical Science and Technology, ShanghaiTech University, Shanghai, 200031, China.|Max Planck Institute for the Physics of Complex Systems, Dresden, 01187, Germany.
authors.forename: Binghai
authors.initials: B
authors.lastname: Yan
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany.
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Medvedev
keywords: high pressure; superconductivity; topological materials