Spin dynamics of the spin-1/2 kagome lattice antiferromagnet ZnCu3(OH)6Cl2.
We have performed thermodynamic and neutron scattering measurements on the S=1/2 kagomé lattice antiferromagnet ZnCu3(OH)6Cl2. The susceptibility indicates a Curie-Weiss temperature of theta CW approximately = -300 K; however, no magnetic order is observed down to 50 mK. Inelastic neutron scattering reveals a spectrum of low energy spin excitations with no observable gap down to 0.1 meV. The specific heat at low-T follows a power law temperature dependence. These results suggest that an unusual spin liquid state with essentially gapless excitations is realized in this kagomé lattice system.
Helton
J S
JS
Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Matan
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K
Shores
M P
MP
Nytko
E A
EA
Bartlett
B M
BM
Yoshida
Y
Y
Takano
Y
Y
Suslov
A
A
Qiu
Y
Y
Chung
J-H
JH
Nocera
D G
DG
Lee
Y S
YS