Kondo effect in single quantum dot systems - Study with numerical renormalization group method
Kondo effect in single quantum dot systems - Study with numerical renormalization group method
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DOI：
10.1143/jpsj.67.2444
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发表时间：
1998-07-01
影响因子：
1.7
通讯作者：
Shimizu, Y
中科院分区：
文献类型：
--
作者：
Izumida, W;Sakai, O;Shimizu, Y
计算了具有库仑相互作用的单量子点系统在宽温度范围内的隧穿电导与栅电压的关系。我们假设两个轨道对于隧穿过程是活跃的。我们发现，近藤温度为每个轨道通道可以在很大程度上是不同的。通过近藤共振的隧穿在小于或近似于0.1T（K）*（类似于0.2T（K）*）的区域T中几乎完全发展，其中T-K* 是当栅极电压变化时的最低近藤温度。在高温下，电导变化为通常的库仑振荡类型。在中温区，各轨道通道的相干程度不同，电导会出现奇怪的行为。例如，当在T = 0处通过不同通道之间的干扰消除来抑制电导时，电导随着温度降低而一度增加然后减小。量子点系统中的相互作用效应导致电导对温度和栅电压的敏感性。
The tunneling conductance is calculated as a function of the gate voltage in wide temperature range for the single quantum dot systems with Coulomb interaction. We assume that two orbitals are active for the tunneling process. We show that the Kondo temperature for each orbital channel can be largely different. The tunneling through the Kondo resonance almost fully develops in the region T less than or similar to 0.1T(K)* similar to 0.2T(K)* where T-K* is the lowest Kondo temperature when the gate voltage is varied. At high temperatures the conductance changes to the usual Coulomb oscillations type. In the intermediate temperature region, the degree of the coherency of each orbital channel is different so strange behaviors of the conductance can appear. For example, the conductance once increases and then decreases with temperature decreasing when it is suppressed at T = 0 by the interference cancellation between different channels. The interaction effects in the quantum dot systems lead the sensitivities of the conductance to the temperature and to the gate voltage.