Polar Ohmic Contact Switching with a Ferroelectric Metal

As the dimension of electronic devices shrinks to electronic screening lengths (<10 nm), electric polarization becomes critical for device performance. Electric polarization has been widely investigated in ferroelectric devices, where nonvolatile polarization switching occurs in ferroelectric dielectrics. Recently, 2D ferroelectric conductors have been discovered, enabling the switching of direct current flow through atomically thin ferroelectric channels. However, elucidating and harnessing the role of nonvolatile polarization switching in transport through ferroelectric channels and atomic-scale interfaces remain challenging. Here, we report switchable polar ohmic contacts and channels formed with 2D ferroelectric WTe₂ and their impact on nonvolatile switching operation. Beyond conventional device control through carrier density and mobility, the polar 2D channel modulates the proximity effect with metal electrodes, resulting in 390 times larger switching performance than solely gating the ferroelectric channel in a two-terminal geometry. Our study highlights the potential of controlling polar ohmic contacts to overcome short-channel effects and enable multiple conductance states for neuromorphic devices.