Even-odd parity oscillations in spin polarization of a quantum dot array

Abstract

We propose a quantum dot (QD) array device which contains a bridge coupling between two leads. Due to the quantum interference and the Rashba spin-orbit interaction, the spin of the electrons through the device is polarized. Moreover, we find odd-even parity oscillations of spin polarization of the electrons through the system. We study the spin accumulations in every QD and find that there is difference between the spin accumulations of the QDs directly and indirectly coupling to leads. These results demonstrate that the bridge coupling is a flexible and feasible way to manipulate the electron spin of the QD array.

Perfect spin-filter and highly spin-polarized current in a quantum network device

“…Because in comparison with single QD structure, the multi-QD structure exhibits much more intricate behaviors due to its more Feynman paths and richer phase-coherent effect in electronic transport. [3][4][5][6] Very recently, to explore a quantum network device composed of the multiple QDs (see Fig. 1) to act as a spin filter has been a hot topic.…”

Aharonov–Bohm ring with a side-coupled quantum dot array as a spin switch

“…[2][3][4][5][6] Transport properties of electrons in a single QD and double QDs side-coupled to a quantum wire or an Aharonov-Bohm ͑AB͒ ring have been investigated extensively in recent years. Quantum dots ͑QDs͒ are among the most studied mesoscopic systems due to their physical properties as well as their potential applications in electronic devices.…”

“…Recently, motivated by the pioneering work of Datta and Das, 1 there have been a great deal of theoretical and experimental work concerning the possibility of controlling the electron spin by means of the Rashba spin-orbit interaction ͑RSOI͒ with or without the help of the magnetic field and the magnetic material. 6 Recently, Ojeda et al 14 have proposed a spin filter device based on a QD array coupled to leads by using Dicke and Fano effects. [7][8][9] Due to the progress in the nanofabrication of quantum devices, it is possible to fabricate long-range ordered QDs arrays.…”

“…6 In the following we present the numerical results. 6 In the following we present the numerical results.…”

Perfect spin-filter and quantum-signal generator in a parallel coupled multiple triple-quantum-dots device

“…Because these systems not only provide many Feynman paths for the electron transmission to exhibit rich transport behaviors but also possess many tunable parameters for us to manipulate the electronic transport. [4][5][6][7] Simulated by the recent great progress in nanotechnology which makes it possible to fabricate long-range or multi-QD arrays, many theoretical works have become increasing concerned about the electronic through various multi-QD arrays, [8][9][10][11][12] which helps us to under-stand the transport behaviors in these systems and presents some simple but reliable designs to realize some particular transport properties based on the basic quantum effects. For example, in the structures with one or several QDs side-coupled to a main conducting channel, some theoretical works showed that a zero point of the linear conductance occurs due to the Fano antiresonance effect.…”