2015 Emerging Leaders

Gretchen K. Campbell

Advanced the emerging field of physics known as atomtronics, paving the way for a new generation of technologies much like electronics has transformed our society today.

Electronics have dramatically changed our lives, making it possible for computers to process information and run everything from automobiles and kitchen appliances to smartphones and spacecraft. Now, scientists are opening up an entirely new frontier, a circuitry system that uses the flow of atoms rather than electrons, which may lead to a wide range of future technological advances.

Gretchen Campbell, a 35-year-old physicist at the National Institute of Standards and Technology (NIST), is a pioneer and intellectual leader of this new and theoretical field of physics known as atomtronics, and has conducted a series of seminal experiments that show its promise and possibilities.

“Her work has been at the center of what is the beginning of a real revolution in the type of things we can do with matter,” said William Phillips, a NIST fellow and Nobel Prize Laureate in physics. “What we are seeing with her work is the dawn of a new kind of opportunity that is analogous to electronics, but has different kinds of opportunities.”

Atomtronics will not supplant electronics, but may offer new kinds of functions. The atomtronic circuit, for example, could be useful in applications such as rotation sensors, improving the functioning of gyroscopes that are used to stabilize spacecraft and airplanes. Someday, the atomtronic circuitry also may be able to perform quantum computations that could offer a significant leap forward in computing speed, performance and capability, and lead to the next generation of technology that will enable smaller and cheaper devices.

Katharine Gebbie, the senior advisor to the director of NIST’s Physical Measurement Laboratory, said “there are very few people who can open up a whole new field.”

“That takes creativity, drive and skill,” said Gebbie. “Gretchen has demonstrated that. She is leading the field.”

Carl Williams, chief of the Quantum Measurement Division at NIST, said Campbell did not come up with the idea of atomtronics, but “all the breakthroughs have been hers” and “everyone is trying to catch her.”

There are two ways to get recognition, Williams added, “Be first or be better. In her case, she’s done both. She’s been the person who has pushed and led the path.”

Just as electronic devices manipulate the flow of electrons, atomtronic devices manipulate the flow of atoms, which are made up of electrons, protons and neutrons. Since atoms have properties that are very different from electrons—they do not, for instance, have charged particles—atomtronic devices have the potential to go beyond the capabilities of electronics.

Using light to control matter, Campbell created the first controllable atomtronic circuit in 2011 by moving ultra-cold atoms through a wire made of light—just as electrons flow through a metal wire. To this simple circuit she added a permeable barrier, also made of light, to serve as the all-important control element, much as a transistor can control the current in an electronic circuit.

“There are lots of opportunities to see how atoms behave. We’re still in the infancy of learning how to control our systems and what we can do,” said Campbell.

Jun Ye, a NIST fellow, said Campbell is an “experimentalist” and is “discovering things completely new.”

“She studies quantum physics using ultra-cold atoms,” said Ye. “This way the atoms slow down and their behavior can be more easily observed. They can exhibit phenomena that they do not exhibit when they are hot.”

Campbell’s achievements include inventing a new technique that would enable an atomtronic circuit to function as the most precise and compact rotation sensor, a new kind of gyroscope that also displays the direction of circulation. She also demonstrated that atomtronic circuits with superfluid properties closely mimic the superconductive properties that can be created in electronic circuits, and she constructed atomtronic circuits that possess hysteresis, which conveys the ability of a circuit to be influenced by its history and not just current conditions.

In addition, Campbell is opening new research directions through the invention of a unique tool that holds mixtures of ultra-cold atoms in a lattice of light, allowing them to be controlled separately and made to interact with each other.

“Even at this early stage of her scientific career, Gretchen Campbell has made a number of truly outstanding contributions,” Ye said. “These successes can be attributed to her outstanding leadership, superior scientific talent and strong work ethic.”

Campbell has mentored numerous graduate students and those doing post doctorate research, co-teaches an atomic physics and quantum optics course at the University of Maryland, and sponsors a women-in-physics group in the Joint Quantum Institute.

Campbell said she is lucky to have gotten in on the ground floor of atomtronics and to have the resources to conduct complicated experiments that can take years to complete.

“I love this field,” she said. “And at NIST, I am blessed with a collaborative environment and great managers who are also supportive scientists.”