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

We report a combined experimental and theoretical study of the dependence ofthe superconductivity of the unconventional superconductor Sr$_2$RuO$_4$ onanisotropic strain. Novel piezoelectric apparatus is used to apply uniaxialpressures of up to $\sim$1~GPa along a $\langle 100 \rangle$ direction($a$-axis) of the crystal lattice. $T_c$ increases from 1.5~K in unstrainedmaterial to 3.4~K at compression by $\approx$0.6\%, then falls steeply. The$c$-axis upper critical field for the strained $T_c$ = 3.4~K material is afactor of twenty larger than that of the unstrained crystal, whereas thein-plane ($a$-axis) critical field increases by only a factor of three.First-principles electronic structure calculations give evidence that theobserved maximum $T_c$ occurs at or near a Lifshitz transition when the Fermilevel passes through a van Hove singularity. Finally, we perform orderparameter analyses using three-band renormalization group calculations. These,combined with the unexpectedly low in-plane critical field, open thepossibility that the highly strained $T_c$=3.4~K Sr$_2$RuO$_4$ has an even-rather than an odd-parity order parameter. Potential implications such as atransition at nonzero strain between odd- and even-parity order parameters arediscussed.

Strong Peak in $T_c$ of Sr$_2$RuO$_4$ Under Uniaxial Pressure