Topological Quantum Phase Transition and Superconductivity Induced by Pressure in the Bismuth Tellurohalide BiTeI |
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| Authors: | Yanpeng Qi Wujun Shi Pavel G. Naumov Nitesh Kumar Raman Sankar Walter Schnelle Chandra Shekhar Fang‐Cheng Chou Claudia Felser Binghai Yan Sergey A. Medvedev |
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| Affiliation: | 1. Max Planck Institute for Chemical Physics of Solids, Dresden, Germany;2. School of Physical Science and Technology, ShanghaiTech University, Shanghai, China;3. Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics”, Russian Academy of Sciences, Moscow, Russia;4. Institute of Physics, Academia Sinica, Taipei, Taiwan;5. Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan;6. Max Planck Institute for the Physics of Complex Systems, Dresden, Germany |
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| 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. |
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| Keywords: | high pressure superconductivity topological materials |
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