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

Bismuthates were the first family of oxide high-temperature superconductors,exhibiting superconducting transition temperatures (Tc) up to 32K, but thesuperconducting mechanism remains under debate despite more than 30 years ofextensive research. Our angle-resolved photoemission spectroscopy studies onBa$_{0.51}$K$_{0.49}$BiO$_3$ reveal an unexpectedly 34% larger bandwidth thanin conventional density functional theory calculations. This can be reproducedby calculations that fully account for long-range Coulomb interactions --- thefirst direct demonstration of bandwidth expansion due to the Fock exchangeterm, a long-accepted and yet uncorroborated fundamental effect in many bodyphysics. Furthermore, we observe an isotropic superconducting gap with2\Delta$_0$/k$_B$ T$_c$ = 3.51 $\pm$ 0.05, and strong electron-phononinteractions with a coupling constant \lambda$\sim$ 1.3 $\pm$ 0.2. Thesefindings solve a long-standing mystery --- Ba$_{0.51}$K$_{0.49}$BiO$_3$ is anextraordinary Bardeen-Cooper-Schrieffer (BCS) superconductor, where long-rangeCoulomb interactions expand the bandwidth, enhance electron-phonon coupling,and generate the high Tc. Such effects will also be critical for finding newsuperconductors.

Unveiling the superconducting mechanism of Ba$_{0.51}$K$_{0.49}$BiO$_3$