Elizabeth McCormack uses laser spectroscopy to study very small molecules. "As a kid I read all sorts of books about the stars, and a lot of science fiction," she says. Growing up, McCormack was inquisitive and curious; she was especially interested in astronomy and the origin of the universe. "Growing up, I was captivated by the big questions --how does the world work and where do we come from?" she says.
McCormack received her bachelor's degree from Wellesley College in 1983 and her Ph.D. in physics from Yale University in 1989. At Yale she joined a group doing precision spectroscopy research on molecular hydrogen. "I would say that was where I had my first experience working with a challenging laser set-up and being impressed by what the technology could do," she notes.
After completing her doctorate, she joined a Photophysics and Photochemistry group at Argonne National Laboratory west of Chicago as a Postdoctoral Research Associate. "I moved from doing precision work in my Ph.D. research to work that was more focused on understanding the structure and dynamics of molecules, especially in their excited states," says McCormack.
At Argonne, McCormack used laser spectroscopy techniques to study simple molecules with environmental relevance, including nitrogen, oxygen, and nitric oxide. She also, along with colleagues developed novel techniques using four wave mixing spectroscopy to look at molecular states.
In 1995 she joined the faculty at Bryn Mawr College in Pennsylvania. "I am actually studying molecular hydrogen again," laughs McCormack. By frequency mixing light of different colors, McCormack creates coherent radiation or laser light, at a wavelength of 193 nanometers. Photons at this wavelength are key to getting into the excited state manifold of molecular hydrogen, where things get interesting.
"In particular, I'm looking at very long range states in molecular hydrogen. These are configurations where the equilibrium distance between the two protons in the molecule is roughly 10 times larger than the ground state of the molecule. And they have very interesting dynamics," explains McCormack.
"The very rich, mixed wave functions of these highly excited states provide an opportunity to explore how to control quantum interactions. We try to use that mixed character to control for example, photodissociation, where if you shape the laser pulse you can direct the molecule into one of several fragment channels. So the notion of using laser light as a way to very precisely control chemical reactions is another area in which the work I do is relevant," she says.
We think of molecular hydrogen as the simplest fundamental molecule, but new laser technologies allow researchers like McCormack to take a different look at even the most simple, well studied systems, and make new discoveries.
When she's not doing research, McCormack enjoys travelling and the outdoors. "One of the fun things about being a research scientist is that you get to travel, I enjoy that aspect. I'm also big on the outdoors, friends and I get together regularly to go camping and kayaking", she says.