Persistent Currents in Normal Metal Rings
Persistent Currents in Normal Metal Rings
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DOI：
10.1103/physrevlett.102.136802
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发表时间：
2009-04-03
影响因子：
8.6
通讯作者：
Moler, Kathryn A.
中科院分区：
文献类型：
--
作者：
Bluhm, Hendrik;Koshnick, Nicholas C.;Moler, Kathryn A.
作者测量了33个单独的冷介观金环的磁响应，一次一个环。一些足够小的环的响应具有在通过环的通量中周期性的分量，并且归因于持续电流。它的周期接近h/e，其符号和振幅在环之间变化。的振幅分布与预测的典型的H/E电流扩散环。测量的四个环的振幅的温度依赖性，也与理论一致。这些结果与先前对三个单独金属环的测量结果不一致，这些测量结果显示出比预期大得多的周期性响应。使用的扫描SQUID显微镜使原位测量的传感器背景。一个顺磁性的线性磁化率和一个鲜为人知的异常周围的零场是由于缺陷自旋。
The authors have measured the magnetic response of 33 individual cold mesoscopic gold rings, one ring at a time. The response of some sufficiently small rings has a component that is periodic in the flux through the ring and is attributed to a persistent current. Its period is close to h/e, and its sign and amplitude vary between rings. The amplitude distribution agrees well with predictions for the typical h/e current in diffusive rings. The temperature dependence of the amplitude, measured for four rings, is also consistent with theory. These results disagree with previous measurements of three individual metal rings that showed a much larger periodic response than expected. The use of a scanning SQUID microscope enabled in situ measurements of the sensor background. A paramagnetic linear susceptibility and a poorly understood anomaly around a zero field are attributed to defect spins.