Spin Dynamics of the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu_3(OH)_6Cl_2

Helton, J. S.; Matan, K.; Shores, M. P.; Nytko, E. A.; Bartlett, B. M.; Yoshida, Y.; Takano, Y.; Suslov, A.; Qiu, Y.; Chung, J. -H.; Nocera, D. G.; Lee, Y. S.

Spin Dynamics of the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu_3(OH)_6Cl_2

Authors

Description

We have performed thermodynamic and neutron scattering measurements on the S=1/2 kagome lattice antiferromagnet Zn Cu_3 (OH)_6 Cl_2. The susceptibility indicates a Curie-Weiss temperature of ~ -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 with exponent less than or equal to 1. These results suggest that an unusual spin-liquid state with essentially gapless excitations is realized in this kagome lattice system.
4 pages, 3 figures; v2: Updates to authors list and references; v3: Updated version; v4: Published version