Complex nanostructures promise to provide a platform for dramatically increasing the efficiency of solar energy conversion into the power and fuels needed for our global future. Nanostructures rely on the dynamics of charge flow between different components within a nanostructure and it is important to develop new methodologies that image their coherent and incoherent dynamics so chemists can manipulate the nanostructure synthesis to optimize its efficiency. We have developed a new family of femtosecond coherent multidimensional spectroscopies that provide movies of the flow of energy with quantum state resolution and require only short term phase coherence. The biggest advantage of short term coherence is the ability to create multiple quantum coherences from any mixture of quantum states using excitation frequencies over the entire spectrum from the infrared to the ultraviolet. The pictures are frames from movies of the flow of energy in two nominally identical PbSe quantum dot samples. The colors represent the population of different quantum states 50 femtoseconds after two previous light pulses excite the sample. There are clearly differences in the flow of the energy in the quantum states because of differences in the surfaces of these nanostructures. There is a very rapid transfer of energy to the surface in the lower sample that can be very important in catalyzing the surface to create a solar fuel. Quantum Resolved Spectroscopy of Excitonic Dynamics in Quantum Confined Nanostructures John C. Wright, University of Wisconsin-Madison, DMR

Our country must lead in both the development of new ideas and scientists. The picture shows an undergraduate student from Professor Peter Chen’s laboratories at Spelman College who participated in this summer’s REU (Research Experiences for Undergraduates) program at Wisconsin. She worked with a graduate student in our laboratories to first synthesize a sample and perform coherent multidimensional spectroscopy. She obtained experience with the chemistry, physics, optics, and ultrafast lasers. She also learned the quantum mechanical background that describes the field and attended seminars by REU faculty, poster sessions with other students, and REU activities. Her experiences provided the background to better understand the interconnections between college courses and real world problems. The picture also contains the icon for this year’s International Conference on Coherent Multidimensional Spectroscopy (CMDS). The conference was started by the P.I. who continues to chair the International Organizing Committee that guides the conference and its goals. The conference is important in disseminating CMDS ideas and technology to the broader scientific community while also providing a forum for the leading scientists and young scientists to meet and exchange ideas. Quantum Resolved Spectroscopy of Excitonic Dynamics in Quantum Confined Nanostructures John C. Wright, University of Wisconsin-Madison, DMR