SciPost Physics

SciPost Phys. 9, 056 (2020) · published 21 October 2020

• doi: 10.21468/SciPostPhys.9.4.056
• pdf
• BiBTeX
• RIS
• Submissions/Reports
• 

Abstract

Charge order -- ubiquitous among correlated materials -- is customarily described purely as an instability of the electronic structure. However, the resulting theoretical predictions often do not match high-resolution experimental data. A pertinent case is $1T$-VSe$_2$, whose single-band Fermi surface and weak-coupling nature make it qualitatively similar to the Peierls model underlying the traditional approach. Despite this, its Fermi surface is poorly nested, the thermal evolution of its charge density wave (CDW) ordering vectors displays an unexpected jump, and the CDW gap itself evades detection in direct probes of the electronic structure. We demonstrate that the thermal variation of the CDW vectors is naturally reproduced by the electronic susceptibility when incorporating a structured, momentum-dependent electron-phonon coupling, while the evasive CDW gap presents itself as a localized suppression of spectral weight centered above the Fermi level. Our results showcase the general utility of incorporating a structured coupling in the description of charge ordered materials, including those that appear unconventional.

• Chua et al., Coexisting Charge-Ordered States with Distinct Driving Mechanisms in Monolayer VSe2
  ACS Nano 16, 783 (2022) [Crossref]
• Watson et al., Spectral signatures of a unique charge density wave in Ta2NiSe7
  Nat Commun 14, 3388 (2023) [Crossref]
• Wang et al., Decisive role of electron-phonon coupling for phonon and electron instabilities in transition metal dichalcogenides
  Phys. Rev. Research 5, 013218 (2023) [Crossref]
• Pouget et al., Momentum-dependent electron-phonon coupling in charge density wave systems
  Phys. Rev. B 103, 115135 (2021) [Crossref]
• Feng et al., Signatures of the charge density wave collective mode in the infrared optical response of VSe2
  Phys. Rev. B 104, 165134 (2021) [Crossref]
• Fumega et al., Anharmonicity Reveals the Tunability of the Charge Density Wave Orders in Monolayer VSe2
  Nano Lett. 23, 1794 (2023) [Crossref]
• Majchrzak et al., Switching of the electron-phonon interaction in 1T−VSe2 assisted by hot carriers
  Phys. Rev. B 103, L241108 (2021) [Crossref]
• Diego et al., Electronic structure and lattice dynamics of 1T−VSe2 : Origin of the three-dimensional charge density wave
  Phys. Rev. B 109, 035133 (2024) [Crossref]
• Mertens et al., Two-Dimensional Discommensurations: An Extension to McMillan’s Ginzburg–Landau Theory
  Condensed Matter 8, 100 (2023) [Crossref]
• Falke et al., Coupling to zone-center optical phonons in VSe2 enhanced by charge density waves
  Phys. Rev. B 104, 235137 (2021) [Crossref]
• Pallikkara Chandrasekharan et al., Carcinogenic dioxane detection using pristine and metal-doped 2D VSe2: Insights from density functional theory simulations
  13, 065024 (2023) [Crossref]