Thursday, August 30, 2007, 1:30 pm — Small seminar room, Bldg. 510
The properties of Mn-doped GaAs are studied at several doping levels and hole
compensations, using a real-space Hamiltonian on an fcc lattice that reproduces
the valence bands of undoped GaAs. Large-scale Monte Carlo (MC) simulations on
a Cray XT3 supercomputer, using up to a thousand nodes, were needed to make
this effort possible. Our analysis considers the spin-orbit interaction
and the random distribution of the Mn ions as well as Coulomb interactions. The hopping amplitudes are
functions of the GaAs Luttinger parameters. At the coupling J~1.2eV deduced
from photoemission experiments, the MC Curie temperature and the shape of the
magnetization curves are in agreement with experimental results for annealed
samples. Although there are sizable differences with mean-field predictions,
the system is found to be closer to a hole-fluid regime than to localized
carriers. Its suitability to study Mn doped GaN and GaP is discussed.
Hosted by: Wei Ku
3835 | INT/EXT | Events Calendar
Not all computers/devices will add this event to your calendar automatically.
A calendar event file named "calendar.ics" will be placed in your downloads location. Depending on how your device/computer is configured, you may have to locate this file and double click on it to add the event to your calendar.
Event dates, times, and locations are subject to change. Event details will not be updated automatically once you add this event to your own calendar. Check the Lab's Events Calendar to ensure that you have the latest event information.