[Todos] Coloquios DF - Ferdinand Schmidt-Kaler (U. Mainz), Jueves 23/10, 14hs, Aula Seminario, 2do piso, Pab. I

[Augusto Roncaglia]

 COLOQUIOS DEL DEPARTAMENTO DE F�SICA FCEYN - UBA


              En el Aula Seminario, 2do piso, Pab. I,

              Jueves 23/10, 14hs:

              FERDINAND SCHMIDT-KALER

              QUANTUM, Institute of Physics, University of Mainz.


*              Modern Quantum Technology with Trapped Ions*


The quantum states of ions are perfectly controlled, and may be used for
fundamental research in quantum physics, as highlighted by the Nobel Prize
given to Dave Wineland in 2012. Two directions of quantum technologies,
followed by the Mainz group, have high impact on solid state physics:
I) The delivery of single cold ions on demand for the deterministic doping
of solid state materials with nm spatial precision to generate
design-structures optimized for quantum processors: Using single ejected
Ca+ ions we reach 8nm wide spot, which can be used for imaging. Co-trapped
N2+ ions have been ejected, this will lead to the fabrication of arrays of
NV center in diamond, well suited for solid state quantum processors.
II) Phase transitions, universal laws of defect formation and non-linear
interactions with trapped ions: Control parameters may be tailored such
that a structural phase transition from a linear to a zigzag configuration
of the crystal is crossed. Trapped ions serve here as a clean model system
to investigate universal laws of defect formation when such transition is
crossed fast and causally separated regions form. The amount of defects is
predicted by the Kibble-Zurek mechanism. We have experimentally determined
the universal scaling exponent for defect formation and confirm the scaling
law for the inhomogeneous Kibble-Zurek effect accurately at the percent
level. Next steps are studies of the Peierls Nabarro potential which keeps
defects trapped in the crystal. Approaching the phase transition at the
critical point is leading to large non-linear interactions of in the ion
crystal normal modes. I will show how the application of multi-dimensional
spectroscopy allows to determine effects such as cross-Kerr coupling or
resonant coupling between vibrational modes, non-linear effects well known
in non-linear optics.
------------ próxima parte ------------
Se ha borrado un adjunto en formato HTML...
URL: http://mail.df.uba.ar/pipermail/todos/attachments/20141017/72f31040/attachment.html