Controlled TwoDimensional Ferromagnetism in 1TCrTe$_2$. The role of charge density wave and strain
Abstract
Transition metal dichalcogenides are promising candidates to show longrange ferromagnetic order in the singlelayer limit. Based on ab initio calculations, we report the emergence of a charge density wave (CDW) phase in monolayer 1TCrTe$_2$. We demonstrate that this phase is the ground state in the singlelayer limit at any strain value. We obtain an optical phonon mode of $1.96$ THz that connects CDW phase with the undistorted 1T phase. Localization of the $a_{1g}$ orbital of CrTe$_2$ produces an outofplane orientation of the magnetic moments, circumventing the restrictions of the MerminWagner theorem and producing ferromagnetic longrange order in the twodimensional limit. This orbitallocalization is enhanced by the CDW phase. Tensile strain also increases the localization of this orbital driving the system to become ordered. CrTe$_2$ becomes an example of a material where the CDW phase produces the stabilization of the longrange ferromagnetic order. Our results show that both strain and phase switching are mechanisms to control the 2D ferromagnetic order of CrTe$_2$.
 Publication:

arXiv eprints
 Pub Date:
 April 2020
 arXiv:
 arXiv:2005.00097
 Bibcode:
 2020arXiv200500097F
 Keywords:

 Condensed Matter  Materials Science
 EPrint:
 J. Phys. Chem. C 2020, 124, 38, 2104721053