Prof. Albert Stolow - University of Ottawa, Canada
Physics Colloquium - Friday, April 4th, 4:30 pm, PSB 161
Ultrafast Molecular Sciences
The
quantum-molecular view of nature led, over the past century, to revolutionary
developments in science and engineering, including spectroscopy, lasers, and
molecular biology/genetics. A cornerstone of this has been the development of
microscopic structure-function relationships. Nature, however, is seldom
static. Therefore, in the 21st century, there is a need to develop a
microscopic but dynamic, rather than static, quantum-molecular view of Nature
and its processes. Unfortunately, we do not yet have “dynamics-function”
relationships. Nevertheless, this quantum dynamical view will be required for
many emerging areas of molecular science and technology including chemical
reaction dynamics, attosecond science, photoactive materials, quantum control,
molecular machines, biomedical imaging etc.
In the general case, molecular dynamics involves the ultrafast rearrangements of both electronic charge and vibrational energy, termed non-adiabatic dynamics. For example, Chemistry, the breaking and making of chemical bonds, necessarily involves the coupled ‘dance’ of valence electronic charge and atomic motions. Ultrafast laser science has led to significant progress in molecular dynamics studies, particularly for the difficult but most general case of non-adiabatic dynamics. We employ photoelectron spectroscopy because it is a uniquely powerful probe technique which combines elements of both scattering theory and spectroscopy [1-3]. Furthermore, new methods in non-perturbative laser quantum control have emerged as important tools for enhancing molecular dynamics studies [4,5], permitting direct measurements within the Molecular Frame which avoid the usual loss of information due to lab frame orientational averaging [6,7]. As laser fields get stronger, a sub-cycle (attosecond) physics emerges, leading to new probes of driven multi-electron dynamics in polyatomic molecules. Ultrafast laser science in condensed phases also offers new opportunities in biophysics. We ‘trigger’ the unzipping of double helix DNA, potentially leading to ‘light-induced genomics’, and simplified approaches to label-free microscopy of live cells and tissues [8], leading to the first commercially available CARS microscope [9]. We anticipate that the dynamical view will lead to important advances in molecular sciences and its manifold of applications.
In the general case, molecular dynamics involves the ultrafast rearrangements of both electronic charge and vibrational energy, termed non-adiabatic dynamics. For example, Chemistry, the breaking and making of chemical bonds, necessarily involves the coupled ‘dance’ of valence electronic charge and atomic motions. Ultrafast laser science has led to significant progress in molecular dynamics studies, particularly for the difficult but most general case of non-adiabatic dynamics. We employ photoelectron spectroscopy because it is a uniquely powerful probe technique which combines elements of both scattering theory and spectroscopy [1-3]. Furthermore, new methods in non-perturbative laser quantum control have emerged as important tools for enhancing molecular dynamics studies [4,5], permitting direct measurements within the Molecular Frame which avoid the usual loss of information due to lab frame orientational averaging [6,7]. As laser fields get stronger, a sub-cycle (attosecond) physics emerges, leading to new probes of driven multi-electron dynamics in polyatomic molecules. Ultrafast laser science in condensed phases also offers new opportunities in biophysics. We ‘trigger’ the unzipping of double helix DNA, potentially leading to ‘light-induced genomics’, and simplified approaches to label-free microscopy of live cells and tissues [8], leading to the first commercially available CARS microscope [9]. We anticipate that the dynamical view will lead to important advances in molecular sciences and its manifold of applications.
Contact: Pat physics AT ucf . edu,
3-2325
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