Extremely long-period charge density wave induced by bilayer splitting in LaTe3.

We investigated the recently discovered extremely long-period stripe structure (ELPSS) in LaTe3using scanning tunneling microscopy (STM)/scanning tunneling spectroscopy. We found that the contrast of the ELPSS was inverted between STM images acquired at positive and negative setup bias voltages, and that the tunneling spectrum exhibited a spatial variation corresponding to the ELPSS. These results indicate that the ELPSS is a charge density wave (CDW) with an energy gap opening near the Fermi energy and suggest that the bilayer splitting induces the formation of this extremely long-period CDW.