Doping tunable charge density waves in misfit layer compounds

Abstract

The ability to tune charge density waves (CDWs) through external control knobs, such as doping, pressure or strain is crucial for exploring the phase diagram of two dimensional (2D) or quasi-2D materials. Yet, controlling CDWs critical temperature and ordering vector remains a challenge for current experimental techniques. In this work, we establish misfit layer compound heterostructures as a reliable platform to manipulate CDWs in transition metal dichalcogenides. By combining ab initio calculations with low-temperature scanning tunneling microscopy, we show how to achieve doping tunable control over NbSe2 CDW by chemically alloying in the rocksalt subunit. Crucially, we prove that tuning the La Pb ratio in the misfit family (LaxPb1xSe)1.14(NbSe2)2 enables stabilization of different CDW orders, such as 2x2 or 3x3 patterns, and even coexisting phases. This work paves the way for engineering transition metal dichalcogenides with tailored charge density waves within misfit heterostructures.