Anomalous electron-electron interactions in epitaxial graphene on SiC. (30th October 2021)

• Record Type: Journal Article
• Authors: Yang, Y.; Gao, K.H.; Wang, W.J.; Yu, G.; Sun, Y.; Zhang, X.H.; Li, Z.Q.
• Is Part Of: Carbon. Volume 184(2021)
• Page Start: 287
• Page End: 294
• Publication Date: 2021-10-30
• Subjects: Electron-electron interactions -- Monolayer graphene -- Gas absorption; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2021.08.028
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Electron-electron interactions (EEI) play a pivotal role in the transport behavior of carriers confined in a two-dimensional system. The strength of the interaction can be tuned by changing carrier concentration in a conventional two-dimensional system, while it expectedly cannot be controlled in monolayer graphene with a linear dispersion relation since the interaction parameter is not related to carrier concentration. Here, an anomalous carrier-concentration dependence of the EEI is observed in epitaxial graphene on SiC. From quantum transport measurement, a logarithmic temperature dependence of the Hall coefficient is obtained, which is a manifestation of the EEI. From the logarithmic temperature dependence, the EEI-related factor K e e is extracted. Unexpectedly, the extracted K e e shows an increase on increasing carrier concentration, which is further confirmed by analyzing logarithmic correction to the Drude conductivity. This can be attributed to the carrier-concentration dependence of Fermi-liquid constant F 0 σ due to gas absorption, which offers a route to control the EEI in graphene. Graphical abstract: Image 1