2015/05/06 by Eunsung Park, Park, Eunsung, Xin Lu +13
Chemistry · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Inorganic Chemistry and Materials #Iron-based superconductors research #Rare-earth and actinide compounds #Superconductivity (cond-mat.supr-con) #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1505.01258
5figures
arxiv created 2015/05/06 · openalex publication_date 2015/05/06 · arxiv updated 2015/05/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present the first direct evidence for two-band superconductivity in the quasi-one dimensional chalcogenide Nb2Pd0.81S5. Soft point contact spectroscopic measurements reveal Andreev reflection in the differential conductance G in the zero-resistance superconducting (SC) state below Tc(=6.6~K). Multiple peaks in G were clearly observed at 1.8~K and were successfully explained by the two-band Blonder-Tinkham-Klapwijk model with two gaps Δ1=0.48~meV and Δ2=1.05~meV. Their evolution in temperature and magnetic field is consistent with the conventional BCS theory. The SC gap to Tc ratio for Δ1 and Δ2 is 1.7 and 3.7, which is similar to the weak coupling BCS prediction of 3.5. These results demonstrate that the newly discovered niobium chalcogenide is a two-gap superconductor in the weak coupling limit.