Ground state and excitation properties of the quantum kagomé system ZnCu${}_3$(OH)${}_6$Cl${}_2$ investigated by local probes

Abstract

We characterize the ground state and excitation spectrum of the $S=1/2$, nominally pure and perfect kagomé system ZnCu${}_3$(OH)${}_6$Cl${}_2$ using the following measurements: magnetization, muon spin rotation frequency shift $K$, transverse relaxation time $T_2^{\ast }$, and zero field relaxation, and Cl nuclear spin-lattice relaxation $T_1$. We found no sign of singlet formation, no long range order or spin freezing, and no sign of spin-Peierls transition even at temperatures as low as 60 mK. The density of states has $E^{1/4}$ energy dependence with a negligible gap to excitation.

5 pages, 5 figures, LaTex; corrected typos

Cited by in corpus (1)

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