Bulletin of the American Physical Society
2008 APS March Meeting
Volume 53, Number 2
Monday–Friday, March 10–14, 2008; New Orleans, Louisiana
Session H1: Single-Ion Magnetic Moments in Semiconductors |
Hide Abstracts |
Sponsoring Units: DCMP Chair: Michael Flatte, University of Iowa Room: Morial Convention Center LaLouisiane AB |
Tuesday, March 11, 2008 8:00AM - 8:36AM |
H1.00001: Single-ion magnetic moments in semiconductors Invited Speaker: The ability to manipulate single spins in a solid-state environment provides a new pathway to study the fundamental physics of magnetism and may lead to the development of nanoscale spin-based quantum devices. Single magnetic ions bound with valence holes in semiconductors are a good candidate for building scalable quantum spin systems that can be directly integrated into conventional charge-based electronics. The highly extended hole wave function is susceptible to external non-magnetic control fields, such as electric or strain fields. The spin-orbit coupling between the orbital and spin character of the bound hole state permits indirect manipulation of the spin states of the magnetic ions. It is also possible to make use of the spin-dependent local density of states to probe the spin state of individual magnetic ions. I will discuss our theoretical understanding on the anisotropic shape of the bound hole states and the resulting anisotropic magnetic interaction. The hole wave function can be significantly altered by a strain field, which in turn influences the magnetic interaction. The magnetic interaction is found to be sensitive to the local changes in the hole binding energy as well. Our results pave the way for electrical manipulation of single ion spins in semiconductors and also shed light on bulk magnetic properties of very dilute magnetic semiconductors. [Preview Abstract] |
Tuesday, March 11, 2008 8:36AM - 9:12AM |
H1.00002: Atom-by-Atom Substitution of Mn in GaAs and Visualization of their Hole-Mediated Interactions Invited Speaker: |
Tuesday, March 11, 2008 9:12AM - 9:48AM |
H1.00003: Zero-field optical manipulation of magnetic ions in semiconductors Invited Speaker: For coherent spin information processing, spin coherence times must be long enough to perform multiple state operations, thus requiring a balance between gating time and spin lifetime. Because single magnetic spins in semiconductors can be strongly coupled to both itinerant carriers and to other magnetic ions, these interactions can be rapidly manipulated optically and electrically. We show that small numbers of magnetic spins in III-V GaAs quantum wells can be polarized by optical spin injection without the need for applied magnetic fields, and exhibit unusually long coherence times \footnote{R. C. Myers, M. H. Mikkelsen, J.-M. Tang, M. E. Flatt\'{e}, A. C. Gossard, and D. D. Awschalom, \textit{submitted} (2007).}. Mn ions provide acceptor states within the bandgap of GaAs \footnote{J. Schneider, U. Kaufmann, W. Wilkening, M. Baeumler, and F. K\"ohl, \textit{Phys. Rev. Lett.} \textbf{59}, 240 (1987).}, enabling optical readout and control of the magnetic ions in a manner distinct from paramagnetic II-VI materials. Spin polarized electrons created within the quantum well dynamically orient the Mn spins in a manner analogous to dynamic nuclear polarization, generating a dynamic exchange splitting of the magnetic spins. The Mn ions are manipulated at zero field solely by changing the excitation helicity or energy. Ion spin lifetimes increase sharply as the concentration is reduced exhibiting T$_{2}^{\ast}$ times exceeding 6 ns at the lowest doping, longer than is typically observed in other magnetic semiconductors. These results indicate that hole-mediated Mn-Mn interactions dominate the decoherence, and suggest that long lifetimes may be expected for single Mn spins in GaAs. [Preview Abstract] |
Tuesday, March 11, 2008 9:48AM - 10:24AM |
H1.00004: The wave function of a single-ion magnetic moment in GaAs Invited Speaker: |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700