Nanoscale Strain and Charge Density Wave State Ordering in Layered Rare-Earth Tellurides

The layered rare-earth tellurides are quasi–two-dimensional materials that are composed of conducting square-planar Te layers separated by insulating rare-earth block layers. These compounds host charge density wave (CDW) states which are primarily confined to the Te net layers. The origin of the CDW instabilities in these materials is of debate and focus on the relevance and importance of Fermi Surface Nesting, momentum-dependent electron-phonon coupling, and other factors such as strain in the formation of the established CDW order.

Our previous scanning tunnelling microscopy measurements [1,2] reveal that the surface Te-net layers in TbTe₃ and CeTe₂ can host unidirectional and bi-directional CDW states (along the in-plane a- and c-axes) with a directional preference related to local lattice strain. In this talk, we examine the connection between nanoscale lattice strain and local observed CDW order. Using scanning tunnelling microscopy, we investigate how local nanoscale strain influences CDW formation and orientation in these materials.



[1] Physical Review B, 101, 245423 (2020).

[2] Physical Review B, 94, 205101 (2016).