1 State Key Laboratory of Surface Physics, Department of Physics, and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China;2 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;3 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;4 Collaborative Innovation Center of Quantum Matter, Beijing 100084, China;5 Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China>
We performed ultra-low temperature thermal conductivity measurements on the single crystal of a new gold-based quasi-two-dimensional superconductor AuTe2Se4/3, which has a superconducting transition temperature Tc=2.70 K. A negligible residual linear term κ0/T in zero magnetic field is observed, which suggests fully gapped superconducting state. Furthermore, the field dependence of κ0/T is similar to that of the multi-band s-wave superconductor BaFe1.9Ni0.1As2 at low field. These results reveal multiple nodeless superconducting gaps in this interesting quasi-two-dimensional superconductor with Berezinsky-Kosterlitz-Thouless topological transition.
Project supported by the Key Basic Research Program of China (Grant Nos.2015CB921401 and 2016YFA0300503),the National Natural Science Foundation of China (Grant Nos.11422429 and 11421404),China Postdoctoral Science Foundation (Grant No.2016T90332),the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning,and STCSM of China (Grant No.15XD1500200),and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No.XDB04040200).