Quantum Monte Carlo and density functional theory study of strain and magnetism in 2D 1T-VSe2 with charge density wave states

Published

March 7, 2025

Author(s)

Daniel Wines, Akram Ibrahim, Nishwanth Gudibandla, Tehseen Adel, Frank Abel, Sharadh Jois, Kayahan Saritas, Jaron Krogel, Li Yin, Tom Berlijn, Aubrey Hanbicki, Gregory Stephen, Adam Friedman, Sergiy Krylyuk, Albert Davydov, Brian Donovan, Michelle Jamer, Angela Hight Walker, Kamal Choudhary, Francesca Tavazza, Can Ataca

Abstract

Two-dimensional (2D) 1T-VSe2 has prompted significant interest due to the discrepancies regarding alleged ferromagnetism (FM) at room temperature, charge density wave (CDW) states and the interplay between the two. We employed a combined Diffusion Monte Carlo (DMC) and density functional theory (DFT) approach to accurately investigate the magnetic properties, CDW states, and their response to strain in monolayer 1T-VSe2. Our calculations show the delicate competition between various phases, revealing critical insights into the relationship between their energetic and structural properties. We performed classical Monte Carlo simulations informed by our DMC and DFT results, and found the magnetic transition temperature (Tc) of the undistorted (non-CDW) FM phase to be 228 K and the distorted (CDW) phase to be 68 K. Additionally, we studied the response of biaxial strain on the energetic stability and magnetic properties of various phases of 2D 1T-VSe2 and found that small amounts of strain can increase the Tc, suggesting a promising route for engineering and enhancing magnetic behavior. Finally, we synthesized 1T-VSe2 and performed Raman spectroscopy measurements, which were in close agreement with our calculated results, validating our computational approach. Our work emphasizes the role of highly accurate DMC methods in advancing the understanding of monolayer 1T-VSe2 and provides a robust framework for future studies of 2D magnetic materials.

Citation

ACS Nano

Pub Type

Journals

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https://doi.org/10.1021/acsnano.4c15914

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Citation

Wines, D. , Ibrahim, A. , Gudibandla, N. , Adel, T. , Abel, F. , Jois, S. , Saritas, K. , Krogel, J. , Yin, L. , Berlijn, T. , Hanbicki, A. , Stephen, G. , Friedman, A. , Krylyuk, S. , Davydov, A. , Donovan, B. , Jamer, M. , Hight Walker, A. , Choudhary, K. , Tavazza, F. and Ataca, C. (2025), Quantum Monte Carlo and density functional theory study of strain and magnetism in 2D 1T-VSe2 with charge density wave states, ACS Nano, [online], https://doi.org/10.1021/acsnano.4c15914, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958089 (Accessed March 29, 2025)