# Manipulating charge-density-wave in monolayer $1T$-TiSe$_2$ by strain and charge doping: A first-principles investigation

## TL;DR

This study uses first-principles calculations to show how strain and charge doping influence charge density wave order in monolayer $1T$-TiSe$_2$, revealing pathways to enhance or suppress CDW and induce superconductivity.

## Contribution

It provides a detailed first-principles analysis of how biaxial strain and charge doping control CDW and potential superconductivity in monolayer $1T$-TiSe$_2$, offering insights for electronic device applications.

## Key findings

- Tensile strain enhances CDW order.
- Compressive strain and doping suppress CDW.
- Potential for inducing superconductivity in doped monolayer $1T$-TiSe$_2$.

## Abstract

We investigate the effects of the in-plane biaxial strain and charge doping on the charge density wave (CDW) order of monolayer $1T$-TiSe$_2$ by using the first-principles calculations. Our results show that the tensile strain can significantly enhance the CDW order, while both compressive strain and charge doping (electrons and holes) suppress the CDW instability. The tensile strain may provide an effective method for obtaining higher CDW transition temperature on the basis of monolayer $1T$-TiSe$_2$. We also discuss the potential superconductivity in charge-doped monolayer $1T$-TiSe$_2$. Controllable electronic phase transition from CDW state to metallic state or even superconducting state can be realized in monolayer $1T$-TiSe$_2$, which makes $1T$-TiSe$_2$ possess a promising application in controllable switching electronic devices based on CDW.