Gate-controlled spin-orbit interaction in InAs high-electron mobility transistor layers epitaxially transferred onto Si substrates

We demonstrate gate-controlled spin-orbit interaction (SOI) in InAs high-electron mobility transistor (HEMT) structures transferred epitaxially onto Si substrates. Successful epitaxial transfer of the multilayered structure after separation from an original substrate ensures that the InAs HEMT maintains a robust bonding interface and crystalline quality with a high electron mobility of 46200 cm²/(V s) at 77 K. Furthermore, Shubnikov-de Haas (SdH) oscillation analysis reveals that a Rashba SOI parameter (α) can be manipulated using a gate electric field for the purpose of spin field-effect transistor operation. An important finding is that the α value increases by about 30% in the InAs HEMT structure that has been transferred when compared to the as-grown structure. First-principles calculations indicate that the main causes of the large improvement in α are the bonding of the InAs HEMT active layers to a SiO₂ insulating layer with a large band gap and the strain relaxation of the InAs channel layer during epitaxial transfer. The experimental results presented in this study offer a technological platform for the integration of III-V heterostructures onto Si substrates, permitting the spintronic devices to merge with standard Si circuitry and technology.