Electrostatically confined charge transport in split-gated MoS2 device

Abstract

As semiconductor scaling approaches the quantum limit, transport phenomena increasingly deviate from classical behavior, necessitating the development of electrostatically defined low-dimensional architectures. Here, we demonstrate one-dimensional (1D)-like charge transport in a gate-defined quantum point contact based on a hexagonal boron nitride (h-BN)-encapsulated few-layer molybdenum disulfide (MoS2) device at cryogenic temperatures. The device exhibits an electron mobility of ∼6600 cm2 V−1 s−1 at 4.2 K, reflecting minimized disorder and a pristine heterostructure interface. A global back-gate controls the carrier density and reduces contact resistance via electrostatic doping at the contacts, while a local top-gate tunes the channel potential. Bottom split gates define a laterally confined conduction channel that can be continuously tuned to pinch-off, enabling precise control of carrier confinement. The observed transport characteristics reveal a transition from two-dimensional to 1D-like transport. These results highlight the potential of multi-gate MoS2 heterostructures for gate-defined quantum devices.