CRC 1242 Outline

Modification of physical properties of condensed matter by external control parameters allow manifold technological applications which have become essential in our daily life. Our understanding of these properties and the development of applications is based on thermodynamics and derived concepts. On a microscopic level the properties' variations correspond in many cases to a non-equilibrium situation whose theoretical treatment is demanding and generally requires concepts beyond thermodynamics. A complete understanding of the temporal evolution of non-equilibrium conditions promises therefore innovative impetus und novel concepts for science and applications. By means of sufficiently short timed external stimuli by, e. g., flashes of light, impulsive change of pressure, voltage surge, or the impact of particles, non-equilibrium situations can be prepared in condensed matter. The strongly excited electronic and phononic degrees of freedom follow dynamics in time and space on characteristic time and length scales in the femtosecond and nanometer range respectively. Experimental access to such dynamics succeeds in particular in the time domain. The paramount goal is to develop a general, microscopic understanding of nonequilibrium states and the respective dynamics. As a result we expect a comprehensive insight and estimations regarding the potential for applications.

To achieve this goal we will advance and integrate available methods in theoretical physics in order to describe the complete evolution in space and time, starting from the instant of the acting stimulus to the local and non-local secondary processes until a situation close to equilibrium is achieved. In order to detect transient electronic and phononic single and many particle distribution functions, propagation effects, and structural as well as cooperative dynamics under nonequilibrium conditions, we will perform time-resolved experiments with femto- to nanosecond resolution. The goal is to prepare non-equilibrium states in condensed matter, to analyze and manipulate their dynamics and as to achieve microscopic understanding through the integration of various experimental and theoretical approaches. We expect to find novel material properties which exist exclusively under non-equilibrium conditions and may be interesting for future applications. In addition to the focus on the active field of nonequilibrium dynamics, a modern graduate education, concerted measures towards equal opportunities, facilitating the compatibility of family and career in science according to the scientists' needs and a result oriented and pedagogical communication with the interested public are essential objectives of the collaborative research center.