Ising and XY paramagnons in two-dimensional 2H-NbSe2
| Autor: | Joaquín Fernández-Rossier, Antonio Costa, Marcio Costa |
|---|---|
| Přispěvatelé: | Universidad de Alicante. Departamento de Física Aplicada, Grupo de Nanofísica |
| Rok vydání: | 2022 |
| Předmět: |
Superconductivity (cond-mat.supr-con)
Condensed Matter - Materials Science Física de la Materia Condensada Condensed Matter - Superconductivity Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Condensed Matter::Strongly Correlated Electrons Paramagnons 2H−NbSe2 monolayers Spin fluctuations |
| Zdroj: | RUA. Repositorio Institucional de la Universidad de Alicante Universidad de Alicante (UA) |
| Popis: | Paramagnons are the collective modes that govern the spin response of nearly magnetic conductors. In some cases they mediate electron pairing leading to superconductivity. This scenario may occur in 2H-NbSe$_2$ monolayers, that feature spin-valley coupling on account of spin-orbit interactions and their lack of inversion symmetry. Here we explore spin anisotropy of paramagnons both for non-centrosymmetric Kane-Mele-Hubbard models for 2H-NbSe$_2$ monolayers described with a DFT-derived tight-binding model. In the infinite wavelength limit we find spatially uniform paramagnons with energies around $1$~meV that feature a colossal off-plane uniaxial magnetic anisotropy, with quenched transversal spin response. At finite wave vectors, longitudinal and transverse channels reverse roles: XY fluctuations dominate within a significant portion of the Brillouin zone. Our results show that 2H-NbSe$_2$ is close to a Coulomb-driven in-plane (XY) spin density wave instability. Comment: 10 pages (6 main text, 4 supplementary material), 10 figures (4 in the main text, 6 in the SM) |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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