[16p-S2_201-1~11] 10.4 半導体・トポロジカル・超伝導・強相関スピントロニクス

16:30 〜 16:45奨励賞エントリー英語発表

[16p-S2_201-10] Epitaxial Growth of Topological Dirac Semimetal α-Sn on Semi-insulating GaAs (001) Substrates

〇(B)Meisei Suzuki¹, Harunori Shiratani¹, Le Duc Anh^1,2, Masaaki Tanaka^1,2 (1.Univ. of Tokyo, 2.CSRN, Univ. of Tokyo)

キーワード：

topological Dirac semimetal、alpha-Sn

α-Sn, an allotrope of tin, exhibits an inverted band structure and can host various topological phases that can be tuned by the film thickness or strain. Establishing a method for fabricating α-Sn thin films on low-cost, large-diameter insulating substrates is essential for understanding the intrinsic physics of α-Sn and for enhancing its potential in device applications. In this study, we grew α-Sn / (In,Al)Sb / GaAs heterostructure on semi-insulating GaAs (001) substrates by molecular beam epitaxy. Despite the significant lattice mismatch, a two-step low- and high-temperature growth for the (In,Al)Sb buffer yielded a very flat surface. The (In,Al)Sb buffer was highly insulating, with its resistivity 10⁴ times larger than α-Sn. Moreover, it imposes in-plane compressive strain on the α-Sn layer, which is expected to drive α-Sn to a topological Dirac semimetal (TDS). These results pave ways to a practical insulating-substrate platform for studying topological nature of α-Sn.