Leturcq R, Schmid L, Ensslin K, Meir Y, Driscoll D C, Gossard A C
Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
Phys Rev Lett. 2005 Sep 16;95(12):126603. doi: 10.1103/PhysRevLett.95.126603. Epub 2005 Sep 15.
We have measured the Kondo effect in a quantum ring connected to three terminals. In this configuration nonlinear transport measurements allow us to check which lead contributes to the Kondo density of states (DOS) and which does not. The ring geometry allows a fine-tuning of the coupling to each lead through the Aharonov-Bohm effect via application of a magnetic field. When the ring is connected to two strongly and one weakly coupled leads, conductance through the weakly coupled lead provides a direct measurement of the DOS in the Kondo regime. By applying a bias between the two strongly coupled leads, we demonstrate directly the splitting of the out-of-equilibrium Kondo DOS.
我们测量了连接到三个终端的量子环中的近藤效应。在这种配置下，非线性输运测量使我们能够确定哪个引线对近藤态密度（DOS）有贡献，哪个没有。通过施加磁场，利用阿哈罗诺夫 - 玻姆效应，环几何结构允许对与每个引线的耦合进行微调。当环连接到两个强耦合和一个弱耦合的引线时，通过弱耦合引线的电导直接测量了近藤区的DOS。通过在两个强耦合引线之间施加偏压，我们直接证明了非平衡近藤DOS的分裂。
