Materials design of a selenium-based TMD superlattice

Two-dimensional, clean-limit superconductors are material platforms for realizing exotic forms of superconductivity. Recent efforts have demonstrated that superlattices composed of superconducting transition metal dichalcogenide (TMD) monolayers and insulating crystalline spacer layers in bulk crystals realize longer mean free path than their exfoliated counterparts [1]. Here we study the previously reported selenium-based layered superconductor, Ba₆Nb₁₁Se₂₈ [2], which is a selenium analog of the sulfur-based TMD superlattice compounds. We present approaches to enhancing electronic mobility through improvements in crystal synthesis, as well as accompanying structural characterization and transport measurements.

1. Aravind Devarakonda, Hisashi Inoue, Shiang Fang, Cigdem Ozsoy-Keskinbora, Takehito Suzuki, Markus Kriener, Liang Fu, Efthimios Kaxiras, David C. Bell, and Joseph G. Checkelsky, Science 370, 231-236 (2020).

2. Ke Ma, Shifeng Jin, Fanqi Meng, Qinghua Zhang, Ruijin Sun, Jun Deng, Long Chen, Lin Gu, Gang Li, and Zhihua Zhang, Phys. Rev. Materials 6, 044806 (2022).