Influence of Dimensionality on the Charge Density Wave Phase of 2H-TaSe2

Published

March 23, 2022

Author(s)

Sugata Chowdhury, Albert Rigosi, Heather Hill, David Newell, Angela Hight Walker, Francesca Tavazza, Andrew Briggs

Abstract

Metallic transition metal dichalcogenides like tantalum diselenide (TaSe2) exhibit exciting behaviors at low temperatures including the emergence of charge density wave (CDW) states. In this work, density functional theory (DFT) is used to classify the effects and influences of van der Waals interactions, most strongly present between the layers of bulk TaSe2 and reduced in monolayer TaSe2, on the CDW atomic structures and resulting phonon properties of those structures. Additional support is provided by experimental phonons seen in Raman spectra as a function of temperature and layer number. A variety of modes are described across several spectral regions and matched to corresponding predicted vibrations, including an experimentally observed forbidden mode. These results highlight the importance of understanding interlayer interactions, which are pervasive in many quantum phenomena involving two-dimensional confinement.

Citation

Advanced Theory and Simulations

Pub Type

Journals

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Keywords

charge density waves, density functional theory, transition metal dichalcogenides, Raman spectroscopy, van der Waals interactions

Citation

Chowdhury, S. , Rigosi, A. , Hill, H. , Newell, D. , Hight Walker, A. , Tavazza, F. and Briggs, A. (2022), Influence of Dimensionality on the Charge Density Wave Phase of 2H-TaSe2, Advanced Theory and Simulations, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=930333 (Accessed October 16, 2025)