The 263^rd Special CMSM Seminar

Germanium spintronics with Co₂-Heusler alloys

 The further developments of semiconductor technologies will become the core of the industries in artificial intelligence, electric vehicles, and some related future technologies. Since an increase in the power consumption in data centers can be one of the serious problems in the near future, novel semiconductor devices with ultra-low power consumption will have to be developed by using technologies other than the miniaturization of the channel length of silicon (Si) metal-oxide-semiconductor field-effect transistors (MOSFET). It has been considered that an enhancement in the current drivability in the MOSFET channel by using germanium (Ge) having higher electron and hole mobility than Si is promising for a technology of next-generation complementary metal oxide semiconductor (CMOS) transistors¹⁾. In addition, the high-quality growth of strained Ge layers on Si can open a way for achieving photonics on the Si platform²⁾. If Ge-based spintronic technologies were also developed on the Si platform, one can achieve a novel electron-photon-spin integrated circuit on Si for ultra-low power consumption electronics (memories) and photonics (telecommunication) in future. In this seminar, we introduce some potentials of Ge and how to integrate spintronics with Ge on Si. To develop Ge-based spintronics devices, we show a method for electrical spin injection/detection at room temperature and highly efficient spin transport using Co₂-Heusler alloy/Ge heterostructures³⁾ and strained SiGe channel⁴⁾, respectively.

1) A. Toriumi and T. Nishimura, Jpn. J. Appl. Phys. 57, 010101 (2018).
2) J. Michel et al., Nat. Photon. 4, 527 (2010).
3) K. Hamaya et al., J. Phys. D: Appl. Phys. 51, 393001 (2018); M. Yamada et al., NPG Asia Mater. 12, 47 (2020).
4) T. Naito et al., Phys. Rev. Applied 13, 054025 (2020); Phys. Rev. Applied 18, 024005 (2022).

Yuya Sakuraba, Magnetic Functional Device Gr.
E-mail: SAKURABA.Yuya[at]nims.go.jp