Origin and strain tuning of charge density wave in LaTe3

Abstract

We study the origin of charge density wave (CDW) in rare-earth tritelluride LaTe3 and the strain tuning effect on CDW in monolayer LaTe3 by first-principles calculations. The calculations of the electronic structure, phonon spectrum, electron susceptibility, and electron-phonon coupling (EPC) matrix show that the origin of CDW in LaTe3 is momentum-dependent EPC rather than Fermi-surface nesting. The unidirectional CDW with a wave-vector QCDW≈2/7c∗ is the most stable state. We study the biaxial strain effect on CDW in monolayer LaTe3 by evaluating the total energy, CDW-related lattice distortions, and phonon spectra. Our results show that the tensile strain can enhance CDW order, while the compressive strain can inhibit CDW order. As the CDW order is fully suppressed, superconductivity could be induced. Our study may help to clarify the mechanism of CDW in LaTe3 and find the effective tuning method of CDW in monolayer or few-layer configuration.