Open AccessUnusual superconductivity in the topological nodal-line semimetal candidate Sn x NbSe2-δ
Author(s) -
Riffat Munir,
K A M Hasan Siddiquee,
Charuni Dissanayake,
K. Kumarasinghe,
Xinzhe Hu,
Y. Takano,
Eun Sang Choi,
Yasuyuki Nakajima
Publication year - 2022
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2164/1/012008
Subject(s) - superconductivity , pauli exclusion principle , condensed matter physics , semimetal , critical field , topology (electrical circuits) , paramagnetism , physics , band gap , mathematics , combinatorics
We report the superconductivity of the topological nodal-line semimetal candidate Sn x NbSe 2- δ with a noncentrosymmetric crystal structure. The superconducting transition temperature T c of Sn x NbSe 2- δ drastically varies with the Sn concentration x and the Se deficiency δ , and reaches 12 K, relatively higher than those of known topological superconductors. The upper critical field of this compound shows unusual temperature dependence, inconsistent with the WHH theory for conventional type-II superconductors. In a low-T c sample, the zero-temperature limit of the upper critical field parallel to the ab plane exceeds the Pauli paramagnetic limit estimated from the simple BCS weak coupling model by a factor of ∼ 2, suggestive of unusual superconductivity stabilized in Sn x NbSe 2- δ . Together with the robust superconductivity against disorder, these observations indicate that Sn x NbSe 2- δ is a promising candidate to explore topological superconductivity.