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

We report a method for determining the spatial dependence of the magneticexchange coupling, $dJ/dr$, from magnetostriction measurements of a quantummagnet. The organic Ni $S = 1$ system NiCl$_2$-4SC(NH$_2$)$_2$ exhibits latticedistortions in response to field-induced canted antiferromagnetism between$H_{c1} = 2.1$ T and $H_{c2} = 12.6$ T. We are able to model themagnetostriction in terms of uniaxial stress on the sample created by magneticinteractions between neighboring Ni atoms along the c-axis. The uniaxial strainis equal to $(1/E)dJ_c/dx_c < S_{\bf r} \cdot S_{{\bf r}+ {\bf e}_c} >$, where$E$, $J_c$, $x_c$ and ${\bf e}_c$ are the Young's modulus, the nearest neighbor(NN) exchange coupling, the variable lattice parameter, and the relative vectorbetween NN sites along the c-axis. We present magnetostriction data taken at 25mK together with Quantum Monte Carlo calculations of the NN spin-spincorrelation function that are in excellent agreement with each other. We havealso measured Young's modulus using resonant ultrasound, and we can thusextract $dJ_c/dx_c = 2.5$ K/$\AA$, yielding a total change in $J_c$ between$H_{c1}$ and $H_{c2}$ of 5.5 mK or 0.25% in response to an 0.022% change inlength of the sample.

Using magnetostriction to measure the spin-spin correlation function and magnetoelastic coupling in the quantum magnet NiCl$_2$-4SC(NH$_2$)$_2$