Single Sublayer Reconstruction in Substrate-Supported WS Twisted Bilayers.

Marginally twisted WS bilayers undergo lattice reconstructions, but it is unclear if the distortion is equally distributed or confined to specific sublayers. Here, we use combined noncontact atomic force microscopy with scanning tunneling spectroscopy to tune the probing depth to extract electronic and atomic lattice information for each sublayer separately. We find a lattice reconstruction unexpectedly confined to the WS layer in contact with graphite only, governed by transition metal dichalcogenide-substrate interactions, leading to a peculiar type of a ferroelectric domain wall.