Observations of Mott Gaps in a Disordered (Ti,V,Cr,Nb,Ta)S₂ Material Studied with Scanning Tunneling Microscopy and Spectroscopy

High entropy materials including high entropy alloys, oxide perovskites, and transition metal dichalcogenides (TMDs), are an interesting family of materials due to their high tunability and multitude of applications. In particular, high entropy van der Waals materials (HEX) are a unique platform to study entropic local interactions and their correlation to larger scale electronic and magnetic properties. Through the use of scanning tunneling microscopy and spectroscopy (STM/S), the atomic resolution topography is measured concomitantly with differential conductance spectra (given by the dI/dV signal), which is related to the local density of states. In this work, we report an observation of the emergence of position dependent gap-like features near the Fermi energy in the metallic dI/dV spectra of a (Ti,V,Cr,Nb,Ta)S₂ HEX crystal. The potential origins, such as the disordered Hubbard model, of the gap-like features and their correlation to the underlying disordered transition metal elements will be discussed.