Seminar for Diploma and Doctorate Students

Tuesdays 9:30 - 12:00 - Seminar Room 4.18 (unless otherwise advertised)

Speakers

27.09.2013 - 10:30h Andreas Buchheit - Dynamik von lasergetriebenen Atomen
Room 4.18
08.10.2013 - 10:30h Katharina Rojan - Optimal Control of the Quantum State of a Microwave Field
Room 4.18
09.10.2013 - 10:30h Masud Haque (MPIKS Dresden) - Non-equilibrium dynamics in isolated quantum systems
Room 4.18
Quantum many-body physics has traditionally been dominated by detailed investigations of equilibrium properties and low-energy excitations.  In the last decade or so, motivated by novel experimental possibilities such as cold atoms, the study of quantum matter far from equilibrium has emerged as an important and exciting new field. I will provide a selection of new questions and phenomena that have appeared in the context of non-equilibrium evolution in isolated systems.  I will detail two examples, namely, (1) the dynamics of composite objects in lattice systems, and (2) Bloch oscillations of many-body systems in a tilted lattice.
22.10.2013 - 10:30 Thomás Fogarty - Correlations in low dimensional quantum systems
Room 4.18
05.11.2013 - 10:30 Daniel Biehl - Quanten- und semiklassische Dynamik von einzelnen Atomen in Resonatoren hoher Güte
Room 4.18
19.11.2013 - 9:00 Giovanni Manfredi (Université de Strasbourg) - Electron dynamics in thin metal films: from Wigner functions to quantum hydrodynamics
Room 4.18
06.12.2013 - 9:00 Giovanni Manfredi (Université de Strasbourg) - Quantum hydrodynamic models for systems of interacting electrons II
Room 4.18
27.01.2014 - 10:30 Giovanni Manfredi (Université de Strasbourg) - Quantum hydrodynamic models for systems of interacting electrons III
SR7 Maths building (room 203)
04.02.2014 - 9:00 Timo Holz - Interactions between Single Atoms and Optomechanical Systems
Room 4.18
11.02.2014 - 9:00 Luigi Giannelli - Super-Adiabatic Transfer in Three-Level Systems
Room 4.18
14.02.2014 - 10:00 Daniel Egger (AG Wilhelm-Mauch)
Room 4.18
Superconducting qubits are electrical circuits put in quantum states. These qubits have transition frequencies of a few GHz and typical coupling strengths of the order of 10-100 MHz. The spectral composition of the control pulses reflects these frequency scales. They can thus be easily created with standard arbitrary waveform generators. Superconducting qubits have much to benifit from complex pulse shaping methods. In this talk we show how to mitigate leakage out of the computational subspace through optimal control methods [Motzoi et al. PRL 103 110501, Schutjens et al. PRA 88 052330]. We also discuss how to improve gates between superconducting qubits [Egger & Wilhelm Supercond. Sci. Tech. 27 014001]. Finally we discuss how to overcome a limitation of optimal control, namely how to mitigate issues linked to the modeling of system.
18.02.2014 - 9:00 Francesco Piazza (TU München) - Umklapp Superradiance from a Collisionless Quantum Degenerate Fermi Gas
Room 4.18
The quantum dynamics of the electromagnetic light mode of an optical cavity filled with a coherently driven Fermi gas of ultracold atoms strongly depends on geometry of the Fermi surface. Superradiant light generation and self-organization of the atoms can be achieved at low pumping threshold due to resonant atom-photon Umklapp processes, where the fermions are scattered from one side of the Fermi surface to the other by exchanging photon momenta. The cavity spectrum exhibits sidebands, that, despite strong atom-light coupling and cavity decay, retain narrow linewidth, due to absorptionless transparency windows outside the atomic particle-hole continuum and the suppression of inhomogeneous broadening and thermal fluctuations in the collisionless Fermi gas.
20.02.2014 - 9:00 Simon Jäger - Strahlungsdämpfung in der Quantenelektrodynamik
Room 4.18