  Large capacitance enhancement is useful for increasing the gate capacitance
of field-effect transistors (FETs) to produce low-energy-consuming devices with
improved gate controllability. We report strong capacitance enhancement effects
in a newly emerged two-dimensional channel material, molybdenum disulfide
(MoS2). The enhancement effects are due to strong electron-electron interaction
at the low carrier density regime in MoS2. We achieve about 50% capacitance
enhancement in monolayer devices and 10% capacitance enhancement in bilayer
devices. However, the enhancement effect is not obvious in multilayer (layer
number >3) devices. Using the Hartree-Fock approximation, we illustrate the
same trend in our inverse compressibility data.
