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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Using an {\it ab initio} approach, we report a phonon soft mode in thetetragonal structure described by the space group $I4_{1}22$ of the $1$ K $5d$superconductor Cd$_2$Re$_2$O$_7$. It induces an orthorhombic distortion to acrystal structure described by the space group $F222$ which hosts thesuperconducting state. This new phase has a lower total energy than the otherknown crystal structures of Cd$_2$Re$_2$O$_7$. Comprehensive temperaturedependent Raman scattering experiments on isotope enriched samples,$^{116}$Cd$_2$Re$_2{^{18}}$O$_7$, not only confirm the already known structuralphase transitions but also allow us to identify a new characteristictemperature regime around $\sim 80$ K, below which the Raman spectra undergoremarkable changes with the development of several sharp modes and modesplitting. Together with the results of the \textit{ab initio} phononcalculations we take these observations as strong evidence for another phasetransition to a novel low-temperature crystal structure of Cd$_2$Re$_2$O$_7$.

Low-Temperature Phase of the Cd$_2$Re$_2$O$_7$ Superconductor: Ab initio Phonon Calculations and Raman Scattering