Stability and Temperature evolution of 2D Ferroelectric d1T-MoTe2 monolayer*

Van der Waals materials are excellent candidates to explore the 2D limit and its potential novel states of matter. In particular, in this talk we will be discussing the ferroelectric state which emerges in the d1T charge density wave of MoTe_2.

MoTe₂ presents a d1T charge density wave (CDW) which has been shown to survive at room temperature [1]. It is this distortion which leads to the emerging polarization that explains the observed ferroelectricity in this 2D system.  In this talk we theoretically demonstrate through ab-initio calculations and anharmonic corrections, the robustness of this ferroelectric phase of MoTe₂. First, we show how the d1T CDW evolves with temperature and how the structure of the compound is affected. The CDW survives through a wide range of temperatures, presenting stable phonons up to 1000K.  We finish our study by characterizing the evolution of the polarization of this system with temperature and therefore its ferroelectric nature at high temperatures.



[1] Yuan, S., Luo, X., Chan, H. L., Xiao, C., Dai, Y., Xie, M., & Hao, J. (2019). Room-temperature ferroelectricity in MoTe2 down to the atomic monolayer limit. Nature communications, 10(1), 1775.