Circular photogalvanic effect in an inversion-symmetry-broken bilayer germanium nanosheet

Taiki Nishijima; Ei Shigematsu; Ryo Ohshima; Keigo Matsushita; Akio Ohta; Masaaki Araidai; Junji Yuhara; Masashi Kurosawa; Masashi Shiraishi; Yuichiro Ando

arXiv · 2411.13947

Circular photogalvanic effect in an inversion-symmetry-broken bilayer germanium nanosheet

Taiki Nishijima·Ei Shigematsu·Ryo Ohshima·Keigo Matsushita·Akio Ohta·Masaaki Araidai·Junji Yuhara·Masashi Kurosawa·Masashi Shiraishi·Yuichiro Ando

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Abstract

Spin-to-charge conversion in monolayer and bilayer germanium(Ge) nanosheets was demonstrated via the circular photogalvanic effect (CPGE). The CPGE current generated in a spin-splitting state of the Ge nanosheet reached a maximum value when the thickness of the Ge nanosheet corresponded to bilayer germanene, indicating that the top layer of the bilayer Ge nanosheet mainly contributed to the spin-to-charge conversion. Because the hybridization of orbitals is suppressed by isolation from the bottom Al layer for the top Ge nanosheet, the observed spin-to-charge conversion has a possibility to be related to the intrinsic features of germanene with breaking of inversion symmetry.

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Taiki Nishijima, Ei Shigematsu, Ryo Ohshima, Keigo Matsushita, Akio Ohta, Masaaki Araidai, Junji Yuhara, Masashi Kurosawa, Masashi Shiraishi, Yuichiro Ando. 2024-11-21. Circular photogalvanic effect in an inversion-symmetry-broken bilayer germanium nanosheet. https://arxiv.org/abs/2411.13947

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