Origin of Giant Rashba Effect in Graphene on Pt/SiC

• Published in: Symmetry (Basel) Vol. 15; no. 11; p. 2052
• Main Authors: Rybkina, Anna, Gogina, Alevtina, Tarasov, Artem, Xin, Ye, Voroshnin, Vladimir, Pudikov, Dmitrii, Klimovskikh, Ilya, Petukhov, Anatoly, Bokai, Kirill, Yuan, Chengxun, Zhou, Zhongxiang, Shikin, Alexander, Rybkin, Artem
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.11.2023
• Subjects: Asymmetry; Carbon; Electromagnetism; Electrons; Energy; Force and energy; Graphene; graphene on silicon carbide; Graphite; Intercalation; Investigations; Metals; Noble metals; Radiation; Rashba spin–orbit coupling; Research parks; Silicon compounds; Silicon substrates; Spectrum analysis; spin-ARPES; Spin-orbit interactions; spin–orbit splitting; Splitting
• ISSN: 2073-8994; 2073-8994
• DOI: 10.3390/sym15112052

Intercalation of noble metals can produce giant Rashba-type spin–orbit splittings in graphene. The spin–orbit splitting of more than 100 meV has yet to be achieved in graphene on metal or semiconductor substrates. Here, we report the p-type graphene obtained by Pt intercalation of zero-layer graphene on SiC substrate. The spin splitting of ∼200 meV was observed at a wide range of binding energies. Comparing the results of theoretical studies of different models with the experimental ones measured by spin-ARPES, XPS and STM methods, we concluded that inducing giant spin–orbit splitting requires not only a relatively close distance between graphene and Pt layer but also the presence of graphene corrugation caused by a non-flat Pt layer. This makes it possible to find a compromise between strong hybridization and increased spin–orbit interaction. In our case, the Pt submonolayer possesses nanometer-scale lateral ordering under graphene.