Theory and Simulation of Laser Dressed Molecules and Materials

Ignacio Franco of the University of Rochester is supported by an award from the Chemical Theory, Models and Computational Methods program in the Division of Chemistry to develop the theory and simulation of the emergent properties of matter when driven or “dressed” by lasers. Characterizing and controlling matter driven far from equilibrium by lasers represents a key challenge for science and technology.

This is because matter can behave very differently when shaken by the intense coherent light provided by lasers. Further, lasers offer the possibility of manipulation on an ultrafast timescale (on the order of a millionth of one billionth of a second), something that is simply not achievable by more conventional means such as an applied voltage, chemical or thermodynamic control.

The Franco group will develop general schemes for the laser control of electrons in matter and, in doing so, catalyze the development of a novel class of laser-dressed dynamical materials with “on-demand" effective properties that are tunable on an ultrafast timescale. Recent proposals by the group include the use of light to drive ultrafast electronic currents, turn insulators into conductors, and optically transparent materials into broadband absorbers.

In addition to the fundamental interest in being able to manipulate electron dynamics with lasers, this ability also serves as the basis for the development of ultrafast electronics, switching, imaging, catalysis, and, in fact, any science and technology at large based on electrons and their control. The outreach activities of this proposal include the organization of annual conferences exploring quantum frontiers in molecular science, integrating research with education by developing a graduate course on “Quantum Dynamics”, and advancing initiatives to increase diversity in STEM at the University of Rochester.

Specifically, the Franco group will investigate the fundamental limits in the quantum control of electrons and advance our capabilities to use high and intermediate intensity ultrafast laser pulses to manipulate electronic properties and dynamics in molecules, nanostructures and extended systems. The group is particularly interested in effects that are triggered by the Stark effect induced by strong non-resonant laser fields.

These fields effectively modify the energy levels in a dynamic and reversible fashion thus creating laser-dressed materials with transient properties that can be very different from those observed near thermodynamic equilibrium. The general objective is to understand the ability of laser-dressed matter to absorb light, transport charge, and the use of light to control electron dynamics.

For this, the group will develop Floquet-based theories of the optical absorption properties of matter, the theory and simulation of laser-driven currents in nanoscale junctions, and advance the use of Stark based strategies to control electron dynamics at material interfaces.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.