By Nicholas Mancusi ’10
A young physicist is chipping away at new corners of a large field.
[Physics] Single-molecule magnets. Quantum tunneling. Ultra-cold atoms. The world of quantum physics is famously impenetrable, if intriguing, to the uninitiated.
That’s why, upon hearing that Michael Foss-Feig ’06 received the 2013 American Physical Society’s Division of Atomic, Molecular and Optical Physics Award for outstanding doctoral thesis in physics (the name alone daunts), a layperson might be tempted to take the physics community’s word for it that it’s a big deal, offer a hearty congratulations and leave it at that. Luckily, Foss-Feig is very good at talking about his thesis and its implications.
Now a postdoctoral fellow in Maryland, he majored in physics and math at Amherst.
To understand his work and that of others in his field, it’s helpful to consider that, counter to common misconceptions about the more recondite pursuits of science, the research has a tangible goal: harnessing the futuristic power of quantum computing. Toward that end, it’s helpful for scientists to first develop what are called “quantum simulators.”
Many technological objects, from barcode scanners to advanced superconducting materials, depend on the strange properties of atomic building blocks so tiny that they adhere to their own set of rules, called “quantum mechanics” (as opposed to the “classical” mechanics used to describe, for example, the action of a basketball rolling down a hill). Predicting the action of a particle that has the boggling ability to be in two places at once can, to say the least, be tricky. To better make sense of these systems, scientists employ quantum simulators, which can be understood as a kind of computer that has only one task, such as predicting how a group of quantum-mechanical particles will act under some prescribed rules of interaction.
“At room temperature a mass of atoms would look like billiard balls flying around and colliding off of each other,” says Foss-Feig. Lasers “push” atoms in the direction opposite their motion, bringing them almost to rest.
Diagram by Ed Wiederer. Diagram source material from Nature.com.
Foss-Feig’s thesis nudged these quantum simulators toward a higher level of complexity, which in turn will be helpful in predicting the properties of more complex quantum material.
One of the many challenges that Foss-Feig faced is that just about any system that would be useful for quantum simulation needs to be very (very, very) cold. By comparison, the few Kelvin degrees above absolute zero that Foss-Feig worked with as an undergraduate while studying single-molecule magnets with Associate Professor of Physics Jonathan Friedman seems positively balmy.
“At room temperature a mass of atoms would look like a room full of billiard balls flying around and colliding off of each other,” Foss-Feig says. “If you want to make them cold enough for their quantum-mechanical nature to be useful, you need to typically achieve a temperature of 1 millionth of a degree above absolute zero. Or colder.”
To achieve this temperature, rather than using some sort of cryogenic tank, as the lay mind might first imagine, scientists employ a system of lasers, shining them on a vapor of atoms isolated in a vacuum. The lasers “push” the atoms in the direction opposite their motion, in a sense holding them as still as possible, which brings them almost to rest. (The glass walls of the vacuum chamber remain room-temperature to the touch, making them 1 billion times hotter than the atoms within.)
Friedman says of his former student: “He wrote a great thesis as an undergraduate, and even came back to work with me over the summer to actually solve the problem, which is quite an accomplishment.”
Foss-Feig is now a postdoctoral fellow at the National Institute of Standards and Technology in Maryland, where he continues his research and splits his time with the University of Maryland. He makes it clear that, although he’s delighted to receive the award, it’s the collaborative nature of science that he enjoys the most. “I’m just chipping away at new corners of a very large field,” he says. Maybe so, but for a scientist just starting his career, he’s chipped off an impressive corner.
Nicholas Mancusi ’10 has a column on The Daily Beast and blogs at Galleyist.com. His writing has appeared in Newsday, American Arts Quarterly and elsewhere.