Non-equilibrium Magnetic Ordering in Quantum Dots

We study semiconductor Quantum Dots (QDs) with magnetic impurities. The magnetism in these systems can be controlled in ways not possible in bulk semiconductors [1]. Robust magnetic effects have been observed recently in both colloidal and self-assembled QDs [2,3]. Here, we develop a rate-equations approach to describe the carrier-mediated magnetic ordering in QDs. In this situation, the magnetic properties are different from the steady-state scenario, due to different carrier spin density, which affects the magnetic-impurity alignment. We focus on a type-II QD band profile, where the electrons reside in the barrier, while the holes are localized in the QD interior, which contains the magnetic impurities. Supported by DOE-BES, US ONR, AFOSR, NSF-DMR and NSF-ECCS CAREER. \\[4pt] [1] R. M. Abolfath, A. G. Petukhov, and I. Zutic, Phys. Rev. Lett. \textbf{101}, 207202 (2008); I. Zutic and A. G. Petukhov, Nature Mater.\textbf{4}, 623 (2009).\\[0pt] [2] R. Beaulac et al., Science \textbf{325}, 973 (2009).\\[0pt] [3] I. R. Sellers, R. Oszwaldowski, et al., Phys. Rev. B \textbf{82}, 195320 (2010).