论文标题
Fano-kondo共振与近距高原与嵌入式量子点的Aharonov-Bohm环
Fano-Kondo resonance versus Kondo plateau in an Aharonov-Bohm ring with an embedded quantum dot
论文作者
论文摘要
我们从理论上检查了带有嵌入式量子点（QD）的Aharonov-bohm环，即所谓的QD干涉仪，以解决有关库仑峰形状的两个有争议的问题，以及通过QD的透射相移的测量。我们扩展了先前的模型[B. R. Bulka和P. Stefanski，物理。莱特牧师。 86，5128（2001）; W. Hofstetter，J。Konig和H. Schoeller，同上。 87，156803（2001）]考虑了两个外部导线中的多个传导通道L和R。我们引入了一个参数P_α（|P_α| \ le 1），以表征环环之间通过铅α（= l，R）之间的连接，这是导导模式之间的重叠积分模式，该模式与两个臂相连。首先，我们在没有电子电子相互作用的情况下研究电导峰值的形状是QD中能级的函数。 = 1在铅中的单个传导通道和| p_ {l，r} |的几乎对称的breit-wigner共振中<0.5在多个通道的情况下。其次，在U.存在的情况下，Bethe Ansatz精确溶液考虑了近藤效应，我们精确地评估了温度t = 0处的电导率，并显示了从不对称的Fano-Kondo共振到Kondo Plateau的交叉，并通过更改P_ {L，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R，R}。我们的模型也适用于QD干涉仪的多末端几何形状。我们通过“双缝实验”在三末端几何形状中讨论了通过QD通过QD的透射相移的测量。我们得出了一个分析表达式，用于测量值和相移的内在值之间的关系。
We theoretically examine the transport through an Aharonov-Bohm ring with an embedded quantum dot (QD), the so-called QD interferometer, to address two controversial issues regarding the shape of the Coulomb peaks and measurement of the transmission phase shift through a QD. We extend a previous model [B. R. Bulka and P. Stefanski, Phys. Rev. Lett. 86, 5128 (2001); W. Hofstetter, J. Konig, and H. Schoeller, ibid. 87, 156803 (2001)] to consider multiple conduction channels in two external leads, L and R. We introduce a parameter p_α (|p_α| \le 1) to characterize a connection between the two arms of the ring through lead α(=L, R), which is the overlap integral between the conduction modes coupled to the two arms. First, we study the shape of a conductance peak as a function of energy level in the QD, in the absence of electron-electron interaction U. We show an asymmetric Fano resonance for |p_{L,R}| = 1 in the case of single conduction channel in the leads and an almost symmetric Breit-Wigner resonance for |p_{L,R}| < 0.5 in the case of multiple channels. Second, the Kondo effect is taken into account by the Bethe ansatz exact solution in the presence of U. We precisely evaluate the conductance at temperature T=0 and show a crossover from an asymmetric Fano-Kondo resonance to the Kondo plateau with changing p_{L,R}. Our model is also applicable to the multi-terminal geometry of the QD interferometer. We discuss the measurement of the transmission phase shift through the QD in a three-terminal geometry by a "double-slit experiment." We derive an analytical expression for the relation between the measured value and the intrinsic value of the phase shift.
