Interplay of thermal and quantum spin fluctuations in the kagome lattice compound herbertsmithite

Citation Wulferding, Dirk et al. " Interplay of thermal and quantum spin fluctuations in the kagome lattice compound herbertsmithite. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. We present a Raman spectroscopic investigation of the herbertsmithite ZnCu 3 ͑OH͒ 6 Cl 2 , a realization of a Heisenberg s =1/ 2 antiferromagnet on a perfect kagome lattice. Focusing on its magnetic excitation spectrum we find two components, a high-temperature quasielastic signal and a low temperature, broad maximum. The latter has a linear low-energy slope and extends to high energy. We have investigated the temperature dependence and symmetry properties of both signals. Our data agree with previous calculations and point to a gapless spin liquid ground state.