$^{13}$C NMR observation of a nonmagnetic charge-ordered state in the organic conductor $κ$-(ET)$_{2}$Hg(SCN)$_{2}$Cl

Fuente: arXiv
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Main Authors: Urai, M., Miyagawa, K., Torunova, S. A., Drichko, N., Zhilyaeva, E. I., Kanoda, K.
Format: Preprint
Published: 2023
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author Urai, M.
Miyagawa, K.
Torunova, S. A.
Drichko, N.
Zhilyaeva, E. I.
Kanoda, K.
author_facet Urai, M.
Miyagawa, K.
Torunova, S. A.
Drichko, N.
Zhilyaeva, E. I.
Kanoda, K.
contents We investigated the local magnetism of the organic conductor, $κ$-(ET)$_{2}$Hg(SCN)$_{2}$Cl, with a quasi-triangular lattice of weakly dimerized molecules through $^{13}$C NMR spectroscopy. The NMR spectra and nuclear relaxation show that charge disproportionation occurs, associated with the metal-insulator transition at 31 K. The relaxation rate indicates that the paramagnetic spins in the insulating phase undergo a transition into a spin-singlet ground state with the emergence of orphan spins, a possible valence-bond-glass state. The present results are in high contrast to the spin-cluster paramagnetism of the electric dipole-liquid candidate, $κ$--(ET)$_{2}$Hg(SCN)$_{2}$Br, having nearly identical material parameters. This fact indicates that these two systems are on the verge between distinct phases in both charge and spin degrees of freedom; a spin-singlet charge-ordered state versus a spin-active Mott insulating state, competing with each other on a triangular lattice of dimerized sites.
format Preprint
id arxiv_https___arxiv_org_abs_2310_08963
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle $^{13}$C NMR observation of a nonmagnetic charge-ordered state in the organic conductor $κ$-(ET)$_{2}$Hg(SCN)$_{2}$Cl
Urai, M.
Miyagawa, K.
Torunova, S. A.
Drichko, N.
Zhilyaeva, E. I.
Kanoda, K.
Strongly Correlated Electrons
We investigated the local magnetism of the organic conductor, $κ$-(ET)$_{2}$Hg(SCN)$_{2}$Cl, with a quasi-triangular lattice of weakly dimerized molecules through $^{13}$C NMR spectroscopy. The NMR spectra and nuclear relaxation show that charge disproportionation occurs, associated with the metal-insulator transition at 31 K. The relaxation rate indicates that the paramagnetic spins in the insulating phase undergo a transition into a spin-singlet ground state with the emergence of orphan spins, a possible valence-bond-glass state. The present results are in high contrast to the spin-cluster paramagnetism of the electric dipole-liquid candidate, $κ$--(ET)$_{2}$Hg(SCN)$_{2}$Br, having nearly identical material parameters. This fact indicates that these two systems are on the verge between distinct phases in both charge and spin degrees of freedom; a spin-singlet charge-ordered state versus a spin-active Mott insulating state, competing with each other on a triangular lattice of dimerized sites.
title $^{13}$C NMR observation of a nonmagnetic charge-ordered state in the organic conductor $κ$-(ET)$_{2}$Hg(SCN)$_{2}$Cl
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2310.08963