Gapless magnetic excitations in the kagome antiferromagnet Ca-kapellasite probed by Cl35 NMR spectroscopy
Gapless magnetic excitations in the kagome antiferromagnet Ca-kapellasite probed by Cl35 NMR spectroscopy
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Cl35 NMR 光谱探测 Kagome 反铁磁体 Ca-kapellasite 中的无间隙磁激发
DOI：
10.1103/physrevb.96.180409
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发表时间：
2017
影响因子：
3.7
通讯作者：
Yoshida H.
中科院分区：
文献类型：
--
作者：
Ihara Y.;Sasaki T.;Noguchi N.;Ishii Y.;Oda M.;Yoshida H.
自旋kagome反铁磁体（Ca-kapellasite）在高达18.9 t的磁场中进行了低能磁激发的aNMR实验研究。最近，Ca-kapellasite被发现是探索kagome反铁磁体本质的最有希望的候选材料之一，因为通过选择具有大离子半径的Ca离子作为反离子，可以最大限度地减少影响本质的磁缺陷。从我们的核自旋-晶格弛豫速率测量中，我们发现在磁有序温度k以下存在幂律温度依赖性，这使我们认为即使在有序状态下，无间隙磁激发也存在。这种幂律行为在强磁场中被抑制。我们讨论了一种可以在低磁场下产生无间隙激励的可能磁态。
The low-energy magnetic excitations of the spin-kagome antiferromagnet(Ca-kapellasite) have been investigated by aNMR experiment in fields up to 18.9 T. Recently, Ca-kapellasite was found to be one of the most promising candidates to explore the intrinsic magnetic properties in kagome antiferromagnets, because magnetic defects, which deteriorate the intrinsic magnetic properties, are minimized by choosing Ca ions with a large ionic radius as the counterions. From our nuclear spin-lattice relaxation ratemeasurement, we found a power-law temperature dependence below the magnetic ordering temperatureK, which leads us to suggest that gapless magnetic excitations survive even in the ordered state. This power-law behavior is suppressed in high magnetic fields. We discuss a possible magnetic state that can generate gapless excitations at low fields.