Aharonov-Bohm ring with a side-coupled atomic cluster: Magnetotransport and the selective switching effect
Aharonov-Bohm ring with a side-coupled atomic cluster: Magnetotransport and the selective switching effect
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DOI：
10.1103/physrevb.77.155310
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发表时间：
2008-04-01
影响因子：
3.7
通讯作者：
Chakrabarti, Arunava
中科院分区：
文献类型：
--
作者：
Jana, Supriya;Chakrabarti, Arunava
我们报告的电子传输特性的一个简单的紧束缚Aharonov-Bohm环线程的磁通量的一个臂，其中一个有限的原子团簇已从一侧连接。我们证明，通过适当地选择在每个臂的量子环的散射体的数量，可以完全阻止跨环的传输时，环是从原子团簇和通量线程环变得等于一半的基本通量量子解耦。当环和杂质团簇之间的耦合被“打开”时，传输共振立即发生。“研究表明，窄的透射共振精确地发生在侧耦合原子链的本征值处。根据环臂中散射体的数量，可以观察到孤立原子团簇的所有本征值或其中一组本征值的“开关”效应。环-点耦合可以逐渐增加以完全抑制磁传输中的振荡。然而，这种抑制可能导致完全透明或根本没有透射，偶尔会伴随着在磁通量的特定值处的相位反转。
We report the electronic transmission properties of a simple tight binding Aharonov-Bohm ring threaded by a magnetic flux to one arm of which a finite cluster of atoms has been attached from one side. We demonstrate that, by suitably choosing the number of scatterers in each arm of the quantum ring, the transmission across the ring can be completely blocked when the ring is decoupled from the atomic cluster and the flux threading the ring becomes equal to half the fundamental flux quantum. A transmission resonance then immediately occurs as the coupling between the ring and the impurity cluster is switched "on." It is shown that narrow transmission resonances precisely occur at the eigenvalues of the side-coupled chain of atoms. The "switching" effect can be observed either for all the eigenvalues of the isolated atomic cluster, or for a selected set of them, depending on the number of scatterers in the arms of the ring. The ring-dot coupling can be gradually increased to completely suppress the oscillations in the magnetotransmission. However, the suppression can lead either to a complete transparency or no transmission at all, occasionally accompanied by a reversal of phase at special values of the magnetic flux.