English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The recent discovery of a charge density wave order at the wave vector $P$$(\frac{1}{3},\frac{1}{3},\frac{1}{3})$ in the kagome metal ScV$_6$Sn$_6$ hascreated a mystery because subsequent theoretical and experimental studies showa dominant phonon instability instead at another wave vector $H$$(\frac{1}{3},\frac{1}{3},\frac{1}{2})$. In this paper, I use first principlestotal energy calculations to map out the landscape of the structuraldistortions due to the unstable phonon modes at $H$, $L$$(\frac{1}{2},0,\frac{1}{2})$, and $P$ present in this material. In agreementwith previous results, I find that the distortions due to the $H$ instabilitycause the largest gain in energy relative to the parent structure, followed inorder by the $L$ and $P$ instabilities. However, only two distinct structureoccur due to this instability, which are separated by 6 meV/f.u. Theinstability at $L$ results in three distinct structures separated in energy by5 meV/f.u. In contrast, six different distorted structures are stabilized dueto the instability at $P$, and they all lie within 2 meV/f.u.\ of each other.Hence, despite a lower energy gain, the condensation at $P$ could be favorabledue to a larger entropy gain associated with the fluctuations within a manifoldwith larger multiplicity via the order-by-disorder mechanism.

Order-by-disorder charge density wave condensation at $\mathbf{\textit{q} =(\frac{1}{3},\frac{1}{3},\frac{1}{3})}$ in kagome metal ScV$_6$Sn$_6$