Tunable spin-orbit splitting in bilayer graphene/WSe$_2$ quantum devices
Jonas D. Gerber, Efe Ersoy, Michele Masseroni, Markus Niese, Michael Laumer, Artem O. Denisov, Hadrien Duprez, Wei Wister Huang, Christoph Adam, Lara Ostertag, Chuyao Tong, Takashi Taniguchi, Kenji Watanabe, Vladimir I. Fal'ko, Thomas Ihn, Klaus Ensslin, Angelika Knothe
公開日: 2025/4/8
Abstract
Bilayer graphene (BLG)-based quantum devices represent a promising platform for emerging technologies, such as quantum computing and spintronics. However, their intrinsically weak spin-orbit coupling (SOC) complicates spin and valley manipulation. Integrating BLG with transition metal dichalcogenides (TMDs) enhances the SOC via proximity effects. While this enhancement has been demonstrated in 2D-layered structures, 1D and 0D nanostructures in BLG/TMD remain unrealized, with open questions regarding SOC strength and tunability. Here, we investigate quantum point contacts and quantum dots in two BLG/WSe$_2$ heterostructures with different stacking orders. Across multiple devices, we reproducibly demonstrate spin-orbit splitting up to 1.5 meV - more than 1 order of magnitude higher than in pristine BLG. Furthermore, we show that the induced SOC can be tuned in situ from its maximum value to near-complete suppression via the perpendicular electric field. This enhancement and in situ tunability establish the SOC as a control mechanism for dynamic spin and valley manipulation.