Spin-polarized currents in double and triple quantum dots driven by ac magnetic fields

Physical review. B, Condensed matter (Impact Factor: 3.66). 11/2010; 82(20). DOI: 10.1103/PhysRevB.82.205304
Source: arXiv


We analyze transport through both a double quantum dot and a triple quantum dot with inhomogeneous Zeeman splittings in the presence of crossed dc and ac magnetic fields. We find that strongly spin-polarized current can be achieved by tuning the relative energies of the Zeeman-split levels of the dots, by means of electric gate voltages: depending on the energy-level detuning, the double quantum dot works either as spin-up or spin-down filter. We show that a triple quantum dot in series under crossed dc and ac magnetic fields can act not only as spin filter but also as spin inverter.

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    • "Spin-inversion in a triple quantum dot under crossed dc and ac magnetic fields has been studied by Busl and Platro [23]. The spin-inverter proposed by Busl and Platro has an important limitation because the inversion of both up and down spins does not occur at the same condition in this type of spin-inverter [23] In a recent study, Fallah and Esmaeilzadeh [24] have shown that, in the presence of proper Rashba SO strength, an organic molecule (1,4-2 phenyl-dithiolate) can act as an electron spin inverter Spin-inversion in nano-scale graphene sheets with a Rashba SO barrier has been studied by Ahmadi et al. [25]. The limitation of this work is that electron spin-inversion depends on the electron incident angle and it can occur only in a finite angular region near the normal incident. "
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