van der Wiel W G, De Franceschi S, Elzerman J M, Tarucha S, Kouwenhoven L P, Motohisa J, Nakajima F, Fukui T
Department of Applied Physics, DIMES, and ERATO Mesoscopic Correlation Project, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, The Netherlands.
Phys Rev Lett. 2002 Mar 25;88(12):126803. doi: 10.1103/PhysRevLett.88.126803. Epub 2002 Mar 7.
We report a strong Kondo effect (Kondo temperature approximately 4 K) at high magnetic field in a selective area growth semiconductor quantum dot. The Kondo effect is ascribed to a singlet-triplet transition in the ground state of the dot. At the transition, the low-temperature conductance approaches the unitary limit. Away from the transition, for low bias voltages and temperatures, the conductance is sharply reduced. The observed behavior is compared to predictions for a two-stage Kondo effect in quantum dots coupled to single-channel leads.
我们报道了在选择性区域生长的半导体量子点中，在高磁场下存在强近藤效应（近藤温度约为4K）。该近藤效应归因于量子点基态中的单重态 - 三重态跃迁。在跃迁时，低温电导接近幺正极限。远离跃迁时，对于低偏置电压和温度，电导会急剧降低。将观察到的行为与耦合到单通道引线的量子点中两阶段近藤效应的预测进行了比较。
