Negative Parabolic Magnetoresistance due to Electron-Electron Interactions in a Disordered 2D Electron Gas in InSe*

Magnetotransport measurements serve as a multifarious tool in understanding various phenomena involved in electron transport, among which the prevalence of the electron–electron interaction (EEI) represents a key aspect with its unique magnetoresistance (MR) signatures. Semiconductor–heterostructure–based, two–dimensional electron gases (2DEGs) have been extensively studied to extract information about the EEI. Two–dimensional (2D) materials may provide more insight into the EEI, possessing an array of materials with extreme versatility in electronic properties. We report negative parabolic MR due to the EEI in a 2DEG formed in InSe, which is a 2D monochalcogenide semiconductor. In this system, we study the EEI in the regime of ω_cτ<1, which is relatively unexplored. A logarithmic relationship between the EEI and the temperature is observed confirming the contribution from the EEI to the MR. We also compare the strength of the observed EEI with other conventional systems such as Si metal–oxide semiconductor field–effect transistors and GaAs quantum wells.