[23p-E205-1~18] 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

▲ [23p-E205-11] Giant spin-to-charge conversion in an all-epitaxial single-crystal-oxide Rashba LaTiO_3+δ/SrTiO₃ heterostructure

〇(D)Shingo Kaneta¹、Miho Kitamura²、Shoma Arai¹、Takuma Arai¹、Ryo Okano¹、Le Duc Anh^1,3,4、Tatsuro Endo¹、Koji Horiba²、Hiroshi Kumigashira^2,5、Masaki Kobayashi^1,6、Munetoshi Seki^1,6、Hitoshi Tabata^1,6、Masaaki Tanaka^1,6、Shinobu Ohya^1,3,6 (1.Univ. of Tokyo、2.KEK、3.IEI, Univ. of Tokyo、4.PRESTO, JST、5.IMRAM, Tohoku Univ.、6.CSRN, Univ. of Tokyo)

キーワード：Spin-to-charge conversion, Two-dimensional electron gas, Oxide heterostructure

The two-dimensional electron gas (2DEG) formed at oxide interfaces, such as LaAlO₃/SrTiO₃ (STO) and AlO_x/STO, has attracted much attention for their extremely large spin-to-charge conversion efficiencies λ_IEE up to ~60 nm due to the large Rashba spin-orbit interaction. However, these insulating layers on STO prevent the propagation of a spin current injected from an adjacent ferromagnetic layer. Moreover, the mechanism of the spin-current flow in these insulating layers is still unexplored. Here, using a strongly correlated polar-metal LaTiO_3+δ (LTO) interlayer and the 2DEG formed at the LTO/STO interface in an all-epitaxial heterostructure, we demonstrate giant λ_IEE up to ~190 nm. The obtained λ_IEE is the highest value among those reported for all materials including metals, semiconductors, and topological systems so far. This highly efficient spin transport/conversion highlights the new hidden inherent possibilities of oxide interfaces for spin-orbitronics applications.