180$^\circ$-twisted bilayer ReSe$_2$ as an artificial noncentrosymmetric semiconductor

S. Akatsuka; M. Sakano; T. Yamamoto; T. Nomoto; R. Arita; R. Murata; T. Sasagawa; K. Watanabe; T. Taniguchi; M. Kitamura; K. Horiba; K. Sugawara; S. Souma; T. Sato; H. Kumigashira; K. Shinokita; H. Wang; K. Matsuda; S. Masubuchi; T. Machida; K. Ishizaka

arXiv · 2309.15403

180$^\circ$-twisted bilayer ReSe$_2$ as an artificial noncentrosymmetric semiconductor

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Abstract

We have fabricated a 180$^\circ$-twisted bilayer ReSe$_2$ by stacking two centrosymmetric monolayer ReSe$_2$ flakes in opposite directions, which is expected to lose spatial inversion symmetry. By the second harmonic generation and angle-resolved photoemission spectroscopy, we successfully observed spatial inversion symmetry breaking and emergent band dispersions. The band calculation shows the finite lifting of spin degeneracy (~50 meV) distinct from natural monolayer and bilayer ReSe$_2$. Our results demonstrate that the spin-momentum locked state, which leads to spintronic functions and Berry-curvature-related phenomena, can be realized even with the stacking of centrosymmetric monolayers.

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S. Akatsuka, M. Sakano, T. Yamamoto, T. Nomoto, R. Arita, R. Murata, T. Sasagawa, K. Watanabe, T. Taniguchi, M. Kitamura, K. Horiba, K. Sugawara, S. Souma, T. Sato, H. Kumigashira, K. Shinokita, H. Wang, K. Matsuda, S. Masubuchi, T. Machida, K. Ishizaka. 2023-09-27. 180$^\circ$-twisted bilayer ReSe$_2$ as an artificial noncentrosymmetric semiconductor. https://arxiv.org/abs/2309.15403

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