Research Area A
Ultrafast dynamics and correlations in small quantum systems
In research area A, our goal is to thoroughly study and precisely control the evolution of photo-induced processes in small quantum systems which are optically driven far above their ground state and whose subsequent dynamics is governed by correlations. The time resolved observation and modelling of such processes represent major challenges to experiment and theory, but holds the promise of providing the most comprehensive description of light-matter interaction and facilitate the development of new mechanisms for dynamically controlling quantum states of matter.
Conceptually situated between area C, where artificial quantum gas systems are prepared with a high degree of control, and area B, being characterized by the complexity and strong coupling of the investigated solid-state materials, research area A takes a bridging position. One direction of development for the second funding term concerns the size of the considered targets. While single atoms remain relevant objects (A1, A3, A5, A6), projects A2 and A3 will investigate multiple charge migration in cyclic hydrocarbons. With increasing number of plaquettes, these systems create a link to graphene-like structures investigated in area B and C. A solid bridge to area B will also be built by project A4 in studies of non-equilibrium quantum dynamics of excitations in solvated transition metal compounds and in anorganic nano-crystals. A strong link to area C will be established by project A6, which aims at simulating atoms employing an ultracold lithium quantum gas and delivering new views on correlation effects in small quantum systems in general.
Light is the key tool for initiating, studying and controlling correlated dynamics in this SFB. In research area A, the high degree of definition of the investigated systems is complemented by the quality of the light tools: All properties of an electromagnetic wave - frequency, polarization, temporal profile and phase – are exploited to a large extent. This includes a large span of photon energies from meV to keV, granting access to tightly bound states (A1-A5) but also facilitating the gentle steering of barely bound electrons (A1). The pulse duration determines the ultimate resolution at which any dynamical evolution can be tracked. Depending on the considered systems, picosecond to attosecond resolution shall be achieved by the experimental projects in order to follow nuclear and electronic motion. The wave nature of light bears the potential of implementing light-phase control of the dynamical evolution of a quantum system. For non-visible wavelengths, the phase-shaping of light remains a considerable challenge, but recent progress in project A2 encourages us to continue evaluating this control parameter. Once successfully established we expect also considerable impact for the possibilities to steer strongly correlated systems in research area B.
The consortium of investigators in research area A will make ample use of the close vicinity to the novel accelerator-based sources of ultra short X-ray pulses in Hamburg. Those greatly extend the capabilities for studying dynamics due to a unique combination of short wavelength, short duration and high intensity. The collaboration will benefit considerably from the mutual utilization of new time-resolving techniques and devices, recently developed by the participating groups.
Individual Projects
| Project | Title | Principal Investigators |
|---|---|---|
| A1 | Electronic correlation in atoms and molecules studied time-resolved with synchronized visible/IR and X-ray pulses | Drescher, Meyer |
| A2 | Coherent control of correlated electron systems with ionizing light fields | Drescher, Laarmann |
| A3 | Electronic correlations in nonlinear processes | Martins, Meyer |
| A4 | Nonlinear spectroscopy of ultrafast electronic correlations in molecular and crystalline spin systems | Bressler, Thorwart, Huse |
| A6 | Anyonic excitations in few-atom fractional quantum Hall systems (associated project) |
Weitenberg |
| A7 | Ultrafast molecular stabilization mediated by electronic correlations |
Calegari, Rubio |