7 June 2013
COBRA COLLOQUIUM: Friday June 7, 2013 at 15:00 – 16:00 in Auditorium room 7 !!!
Speaker: Prof. dr. Manfred Bayer
Title: Coherent manipulation of carrier spins in quantum dot ensembles
Abstract: The three-dimensional confinement in quantum dots leads to long-lived carrier spin coherence. In this presentation we will present a methodology which allows one to assess the coherence time quantitatively: the so-called mode-locking of the precession of an ensemble of electron or hole spins about an external magnetic field with the periodic pulsed laser excitation by which the spins become also oriented. Further, rotation of the spins by laser pulses will be demonstrated as well as establishment of an entanglement-creating interaction between two distinct spin ensembles. This entanglement shall be demonstrated by all-optical tomography.
Biography: Manfred Bayer has studied physics at the University of Wuerzburg, finishing with a diploma thesis in theoretical elementary particle physics. He obtained his PhD in 1997 with a thesis on magneto-photoluminescence studies of semiconductor nanostructures. After his habilitation with optical spectroscopy of III/V semiconductors in 2000 he was appointed as full professor to TU Dortmund University in 2002. He chairs a laboratory covering a wide range of time-integrated and time-resolved laser spectroscopiy techniques, both linear and non-linear.
After the colloquium (around 16:00) we organize a mini-colloquium in which three COBRA researchers, one from each of the three COBRA groups, will give a short presentation about his or her work.
For the Electro Optical Communication Group:
Speaker: Shihuan Zou Title: MIMO Wireless LAN transmission over fiber for in-building network
For the Photonic Integration Group:
Speaker: Dima Dzibrou Title: Two-section polarization converter in generic integration platform
For the Photonics and Semiconductor Nanophysics Group:
Speaker: Joost van Bree Title: Measuring the separate electron and hole g-factors of InAs/InP quantum dots
The audience is invited to an informal gathering following the colloquium in the canteen of the Auditorium, section G!!!