Brandeis University

Columbia University

The Columbia University Keck team proposes to develop a fundamentally new type of energy conversion process, one in which a single absorbed photon creates two or more electronic excitations in a suitable nanostructured material. The physics of this process will be carefully studied and optimized, through control of nanostructure design, by an interdisciplinary team with expertise in chemistry, physics and engineering. This program will build and electrically characterize individual nanoscale photovoltaic devices based on semiconductor nanocrystals and carbon nanotubes. This project has the potential to dramatically improve both basic understanding of non-traditional energy conversion processes and the practical production of electricity and fuels from sunlight.

Stanford University

This project seeks to advance early theoretical and experimental work on the quantum spin Hall system, a newly discovered type of material inside which the laws of electricity and magnetism are dramatically altered. Discovery of such new states of quantum matter could have profound implications on not only fundamental science but also computing technology. When electrons flow through metals or semiconductors, they dissipate energy as heat, causing devices to draw extra power and limiting computer processor speed. Such power dissipation is already the greatest roadblock to scaling semiconductor devices according to Moore’s Law. It is possible to move electrons without dissipation, but known methods have proved impractical, involving extremely low temperatures or large magnetic fields. Recently, a new type of dissipationless transport based on electron spin, rather than charge, has been discovered: the so-called quantum spin Hall (QSH) state in HgTe quantum wells. So far this phenomenon has been limited to cryogenic temperatures. The Stanford team proposes to experimentally test their theoretical prediction that a new class of materials could display the QSH effect at room temperature. Such a breakthrough would deepen understanding of this new state of matter and open the door to new dissipationless computing devices that would manipulate electrons by both charge and spin.

University of California, Berkeley

The next scientific frontier in time-resolved dynamics is the production and utilization of pulses of light in the attosecond time domain (l attosecond = 10-18 seconds). These pulses of light, which can now be generated in the soft X-ray regime of the electromagnetic spectrum, allow scientists to address dynamics on the timescale of electronic motion directly for the first time. The goal of this project is to apply isolated attosecond pulses for the first time to the science of solid-state materials, with particular future applications to solar photovoltaic and related semiconductor materials. The first steps in the formation of charge carriers in photovoltaic devices occur on exceptionally short natural timescales, governed by the rearrangements of electrons in orbitals and electronic bands in materials. By developing a laser laboratory dedicated to the measurement of such solid state electron dynamics, the project will (1) advance the field of short time processes through understanding electron dynamics on an unprecedented level, and (2) unearth mechanisms that will ultimately improve the efficiency of photovoltaic devices. While considerable sources of support are available for short-term exploration of devices and materials, such advances considered here may play a key long-term role in developing newly efficient energy production schemes in the decades to come.

University of Chicago

One of the grand-challenge questions in the physical and biological sciences is how molecular interactions can enable processing of complex information. The answer requires transcending the advances of the genomics and proteomics revolutions to probe and analyze the function of networks of regulatory interactions in cells directly. While there are various means for detecting the presence of molecules, even in spatially and temporally resolved fashions, there is no reliable, standard way to elucidate the collective molecular dynamics that lead to function. We propose to develop the prototype of just such a robust and systematic method – a “chemical perturbation spectroscopy” – that we envision would become a widely used tool for revealing the underlying design and control structures of molecular networks. If successful, the research would be transformative, introducing a totally new approach for probing regulatory interactions systematically, elucidating design principles for cells, developing a theory for driven complex systems, and even enabling the control of cellular dynamics for a broad range of purposes.