Density-dependent spin susceptibility and effective mass in monolayer MoSe₂

Abstract Atomically thin MoSe 2 is a promising platform for investigating quantum phenomena due to its large effective mass, high crystal quality, and strong spin–orbit coupling. In this work, we demonstrate a triple-gate device design with bismuth contacts, enabling reliable ohmic contact down to low electron densities, with a maximum Hall mobility of approximately 22 000 cm 2 Vs −1 at 1.8 K. Low-temperature transport measurements illustrate metal-insulator transitions, and density-dependent quantum oscillation sequences. Enhanced spin susceptibility and density-dependent effective mass are observed, attributed to interaction effects and valley polarization. These findings establish monolayer MoSe 2 as a versatile platform for further exploring interaction-driven quantum states.