Affleck I, Simon P
Canadian Institute for Advanced Research, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1.
Phys Rev Lett. 2001 Mar 26;86(13):2854-7. doi: 10.1103/PhysRevLett.86.2854.
A fundamental prediction of scaling theories of the Kondo effect is the screening of an impurity spin by a cloud of electrons spread out over a mesoscopic distance. This cloud has never been observed experimentally. Recently, aspects of the Kondo effect have been observed in experiments on quantum dots embedded in quantum wires. Since the length of the wire may be of order the size of the screening cloud, such systems provide an ideal opportunity to observe it. We point out that persistent current measurements in a closed ring provide a conceptually simple way of detecting this fundamental length scale.
近藤效应标度理论的一个基本预测是，杂质自旋会被在介观距离上扩展的电子云所屏蔽。这种电子云从未在实验中被观测到。最近，在嵌入量子线的量子点实验中观测到了近藤效应的一些方面。由于量子线的长度可能与屏蔽云的大小相当，这类系统提供了观测它的理想机会。我们指出，在闭环中进行持续电流测量提供了一种从概念上简单的方法来检测这个基本长度尺度。
