Karrasch C, Hecht T, Weichselbaum A, Oreg Y, von Delft J, Meden V
Institut für Theoretische Physik, Universität Göttingen, 37077 Göttingen, Germany.
Phys Rev Lett. 2007 May 4;98(18):186802. doi: 10.1103/PhysRevLett.98.186802. Epub 2007 May 1.
Transmission phase alpha measurements of many-electron quantum dots (small mean level spacing delta) revealed universal phase lapses by pi between consecutive resonances. In contrast, for dots with only a few electrons (large delta), the appearance or not of a phase lapse depends on the dot parameters. We show that a model of a multilevel quantum dot with local Coulomb interactions and arbitrary level-lead couplings reproduces the generic features of the observed behavior. The universal behavior of alpha for small delta follows from Fano-type antiresonances of the renormalized single-particle levels.
多电子量子点（平均能级间距δ较小）的传输相位α测量揭示了连续共振之间普遍存在π的相位突变。相比之下，对于只有少数电子的量子点（δ较大），相位突变的出现与否取决于量子点参数。我们表明，具有局域库仑相互作用和任意能级-引线耦合的多能级量子点模型再现了观察到的行为的一般特征。对于小δ时α的普遍行为源于重整化单粒子能级的法诺型反共振。
