Charge disproportionation in the spin-liquid candidate $\kappa$-(ET)${}_2$Cu${}_2$(CN)${}_3$ at 6 K revealed by ${}^{63}$Cu NQR measurements

T. Kobayashi, Q. -P. Ding, H. Taniguchi +3

The spin-liquid candidate $\kappa$-(ET)${}_2$Cu${}_2$(CN)${}_3$ [ET: bis(ethylenedithio)tetrathiafulvalene] does not exhibit magnetic ordering down to a very low temperature, but shows a myst…