Charge Density Waves in Single- and Bi-layer Bismuth Deposited on NbSe2

A connected low-temperature scanning tunneling (STM) and a molecular-beam epitaxy (MBE) chambers have been used to measure ultra thin films of bismuth (Bi) on NbSe2 single crystals. Due to large lattice mismatch between NbSe2 and Bi we observed two different lattice structures; when a single Ml of Bi is deposited a triangular lattice commensurate with the cleaved NbSe2 is seen and 1D charge density waves (CDW) patter is observed. Instead for thickness bigger than 1 Ml, the topography shows a structure corresponding to (110) Bi oriented film, which also exhibits both 2D and 1D CDW order.