title: Superconductivity in Potassium-Doped Metallic Polymorphs of MoS2.
abstract: Superconducting layered transition metal dichalcogenides (TMDs) stand out among other superconductors due to the tunable nature of the superconducting transition, coexistence with other collective electronic excitations (charge density waves), and strong intrinsic spin-orbit coupling. Molybdenum disulfide (MoS2) is the most studied representative of this family of materials, especially since the recent demonstration of the possibility to tune its critical temperature, Tc, by electric-field doping. However, just one of its polymorphs, band-insulator 2H-MoS2, has so far been explored for its potential to host superconductivity. We have investigated the possibility to induce superconductivity in metallic polytypes, 1T- and 1T'-MoS2, by potassium (K) intercalation. We demonstrate that at doping levels significantly higher than that required to induce superconductivity in 2H-MoS2, both 1T and 1T' phases become superconducting with Tc = 2.8 and 4.6 K, respectively. Unusually, K intercalation in this case is responsible both for the structural and superconducting phase transitions. By adding new members to the family of superconducting TMDs, our findings open the way to further manipulate and enhance the electronic properties of these technologically important materials.
authors.affiliation: School of Physics and Astronomy and ‡School of Earth, Atmospheric, and Environmental Sciences, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Renyan
authors.initials: R
authors.lastname: Zhang
authors.affiliation: School of Physics and Astronomy and ‡School of Earth, Atmospheric, and Environmental Sciences, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: I-Ling
authors.initials: IL
authors.lastname: Tsai
authors.affiliation: School of Physics and Astronomy and ‡School of Earth, Atmospheric, and Environmental Sciences, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Chapman
authors.affiliation: School of Physics and Astronomy and ‡School of Earth, Atmospheric, and Environmental Sciences, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Khestanova
authors.affiliation: School of Physics and Astronomy and ‡School of Earth, Atmospheric, and Environmental Sciences, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Waters
authors.affiliation: School of Physics and Astronomy and ‡School of Earth, Atmospheric, and Environmental Sciences, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Irina V
authors.initials: IV
authors.lastname: Grigorieva
mesh_terms: D002384:Catalysis; D018011:Chalcogens / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry*; D004553:Electric Conductivity; D008982:Molybdenum / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry*; D013696:Temperature
chemical_list: D018011:Chalcogens; D004220:Disulfides; D008982:Molybdenum; D011188:Potassium; C082964:molybdenum disulfide
keywords: Superconductivity; alkali metal intercalation; metallic 1T phase; molybdenum disulfide; transition-metal dichalcogenides