Theoretical Condensed Matter Physics
This year at the Dutch Research School for Theoretical Physics AIO/OIO School for Statistical Physics and Theory of Condensed Matter (aka the DRSTP SPTCM School 2011) I gave some introduction to the idea of linear spin-wave theory and how it can be applied to interlayer excitons. More information on the school itself can be found here, the presentation itself can be downloaded below.
Title: Excitons and spins in strongly correlated systems (pdf, 741 kB)
This years contribution to the annual FOM meeting in Veldhoven is a poster entitled “Exciton motion in strongly correlated heterostructures” (PDF, 700 kB). It was a combined poster with my collaborators from Twente (Marcel Hoek, Francesco Coneri and Hans Hilgenkamp), who were responsible for the experimental part; and with Kai Wu and Jan Zaanen, my theoretical colleagues in Leiden.
Today Kai Wu and I gave a presentation at Jan Zaanen’s group meeting called the “Stripe Club”. Our presentation was named “The motion of a single exciton in a bilayer quantum antiferromagnet” (PDF, 1.9 MB). In summary: we developed a spin wave theory for the bilayer Heisenberg model in order to describe the motion of an exciton through such a bilayer, which we solved using the self-consistent Born approximation. Recently, we obtained numerical results for the exciton spectral function. It appears to be that the Ising-type ladder spectrum reappears even though quantum fluctuations are taken into account, as you can see in the following ‘teaser’ result for alpha=0.2.
My colleagues at the Twente University and me together presented a poster at the MESA+ Institute for Nanotechnology Meeting 2010 held in Enschede at 14 September. The title of our poster was “Bose-Einstein condensation of excitons in oxide heterostructures” and can be downloaded (3.7 MB).
Last week at the Casimir Spring School 2010 I was invited to give a talk on my work on ‘Flux Quantization in Double Layer Exciton Superfluids’. With this talk I was awarded the prize for best oral presentation! 🙂 You can download the presentation here in Powerpoint-format. Note that this talk is intended for general physics PhD-audiences. A more theoretical talk can be found here.
Title:Â Flux Quantization in Double Layer Exciton Superfluids (pptx, 7.5 MB)
Abstract: We predict an unconventional magnetic flux quantization effect to occur in double layer exciton superfluids and we discuss designs for a device to measure this universal electromagnetic signature of the exciton superfluid. This would provide an unambiguous test for the macroscopic phase coherence associated with an exciton Bose-Einstein Condensate.
At the Dutch Research School for Theoretical Physics AIO/OIO School for Statistical Physics and Theory of Condensed Matter (aka the DRSTP SPTCM School 2010) I gave the following presentation on flux quantization in the exciton double layers. Note that this talk is aimed at a theoretical PhD-students level.
Title:Â Magnetic Flux Quantization in Double Layer Exciton Superfluids (pptx, 7.9 MB)