Electron spin-polarization by means of Zeeman and Aharonov-Bohm effects in a double quantum dot ring

A mesoscale Aharonov-Bohm (AB) ring with a quantum dot (QD) embedded in each arm is studied with a tight-binding model for unique transmission properties arising from a combination of AB effects and Zeeman splitting of the QD energy levels. Theoretical analysis of this system has shown that resonance sharpening of the AB oscillation peaks occurs in a balanced ring near resonance, giving sensitive flux-dependence transmission [1]. Combining this effect with Zeeman splitting allows sensitive control of the spin-polarized output of the device. Weighted spin polarization results as a function of electron energy, perpendicular magnetic flux, parallel magnetic field, and QD coupling and energy levels are presented. In cases with perpendicular flux, the AB-oscillations exhibit non-periodicity, due to a flux-dependent shift in the QD energy levels via the Zeeman effect. \\[4pt] [1] E. R. Hedin, Y. S. Joe, and A. M Satanin, Jnl. of Computational Electronics, \textbf{7}, 280 (2008).