2025-05-05 コロンビア大学
＜関連情報＞
- https://magazine.columbia.edu/article/scientists-edge-closer-affordable-superconductors
- https://www.nature.com/articles/s41586-024-08381-1
5.0°ツイスト二層WSe2の超伝導性 Superconductivity in 5.0° twisted bilayer WSe2
Yinjie Guo,Jordan Pack,Joshua Swann,Luke Holtzman,Matthew Cothrine,Kenji Watanabe,Takashi Taniguchi,David G. Mandrus,Katayun Barmak,James Hone,Andrew J. Millis,Abhay Pasupathy & Cory R. Dean
Nature Published:22 January 2025
DOI:https://doi.org/10.1038/s41586-024-08381-1
Abstract
The discovery of superconductivity in twisted bilayer and trilayer graphene1,2,3,4,5 has generated tremendous interest. The key feature of these systems is an interplay between interlayer coupling and a moiré superlattice that gives rise to low-energy flat bands with strong correlations6. Flat bands can also be induced by moiré patterns in lattice-mismatched and/or twisted heterostructures of other two-dimensional materials, such as transition metal dichalcogenides (TMDs)7,8. Although a wide range of correlated phenomena have indeed been observed in moiré TMDs9,10,11,12,13,14,15,16,17,18,19, robust demonstration of superconductivity has remained absent9. Here we report superconductivity in 5.0° twisted bilayer WSe2 with a maximum critical temperature of 426 mK. The superconducting state appears in a limited region of displacement field and density that is adjacent to a metallic state with a Fermi surface reconstruction believed to arise from AFM order20. A sharp boundary is observed between the superconducting and magnetic phases at low temperature, reminiscent of spin fluctuation-mediated superconductivity21. Our results establish that moiré flat-band superconductivity extends beyond graphene structures. Material properties that are absent in graphene but intrinsic among TMDs, such as a native band gap, large spin–orbit coupling, spin-valley locking and magnetism, offer the possibility of accessing a broader superconducting parameter space than graphene-only structures.
