Adjunct Professor and JQI Fellow Ian Spielman has been named a fellow of the American Association for the Advancement of Science (AAAS) in recognition of his research that uses ultracold atoms to study a broad range of topics. 

Each year, AAAS selects scientists, engineers and other innovators to be fellows in recognition of their significant contributions to science.

“It was a complete surprise,” says Spielman, who is also a National Institute of Standards and Technology (NIST) Fellow and a Senior Investigator at the National Science Foundation Quantum Leap Challenge Institute for Robust Quantum Simulation. “I'm super honored to have been selected.”

Spielman leads a research group that studies many-body physics, which describes the complex results of hundreds or more quantum particles interacting. In particular, the group studies gases of atoms at ultracold temperatures—cooling them to just fractions of a degree above absolute zero. Spielman and his colleagues use their experiments with ultracold atoms to simulate and study a variety of topics, from the quantum properties of materials to waves stretching in an expanding one-dimensional universe.Ian Spielman

“We take some of the coldest stuff in the universe, ultracold, ultra-quantum, and use that to study stuff relevant to anyone else,” Spielman says. “So we cherry-pick what's interesting and try to study physics which is hard to study in the other system.”

The AAAS acknowledged Spielman for his experiments using ultracold atoms to study four topics: synthetic magnetic and gauge fields, topological band structures, zitterbewegung and cosmological expansion. These diverse phenomena occur in drastically different circumstances in nature, but, working with a variety of collaborators, Spielman has recreated and studied them using ultracold atoms.

“Ian has done pioneering research at the intersection of condensed matter and atomic physics, in showing how many-body systems can be realized using ultracold atoms,” says Kartik Srinivasan, the NIST Co-Director of JQI. “His election is richly deserved.”

Spielman began using ultracold atoms to study synthetic magnetic and gauge fields early in his career. He and his colleagues used lasers to make the atoms behave as if there was a field—like a magnetic field­—that isn’t actually present in the experiment. In other experiments, Spielman and his colleagues mirrored the effect of spin-orbit coupling, where a quantum particle’s property of spin—a property closely related to its behavior in a magnetic field­—is tied to its motion.

Being able to recreate these effects on demand opened the door to studying a variety of naturally occurring phenomena that generally occur in situations that are challenging to study. For instance, Spielman used clouds of ultracold atoms to study topological band structures, which describe how electrons behave when moving through certain materials. Topological physics underpins how scientists define measurements of electrical resistance and is the foundation of several proposals for error correction in quantum computing. 

To understand the properties of materials with topological band structures, researchers need to consider the simultaneous behavior of all the electrons in the material to properly understand how they contribute to its properties. Spielman created experiments where ultracold atoms can be described using topological band structures similar to those that occur for electrons in topological materials. It can be difficult for researchers to study topological phenomena occurring inside a solid material, but by recreating the behaviors with ultracold atoms, Spielman has helped tease out the underlying physics.

Spielman went on to repurpose the techniques he used to produce synthetic fields and spin-orbit coupling to explore the ways individual quantum particles are predicted to behave when they have a lot of energy, specifically the phenomenon of zitterbewegung (a German word for jittery motion). Zitterbewegung is a theorized rapid oscillation over a very small distance. Scientists have predicted electrons and other particles will experience it when traveling near the speed of light or in other extremely energetic situations. However, researchers haven’t been able to observe the subtle jittering in any fundamental particles. Spielman and his colleagues used ultracold atoms to create an equivalent situation and observe the zitterbewegung jittering of clouds of atoms.

Spielman has also used ultracold atoms to study physics that plays out on a completely different scale: the expansion of the universe. In experiments with JQI Fellow Gretchen Campbell and other colleagues, Spielman trapped a ring of ultracold atoms in a two-dimensional plane and made it either expand or contract. While this bears little resemblance to our universe, the researchers studied sound waves passing through the atoms to learn about the similar behaviors of waves of light traveling in a one-dimensional universe as it changes size.

In these experiments, Spielman and his colleagues investigated the ways waves are stretched and compressed by the universe changing around them. They also studied Hubble damping, an effect that is believed to have helped our actual universe cool down from its initial hot state.

Moving forward, Spielman plans to explore these topics further and to use his ultracold atoms to study additional areas of physics. He credits his collaborators for contributing to his success in his diverse research projects.

“I've benefited greatly from working with a lot of senior colleagues, both just in extended discussions and collaboration,” Spielman says. “That's been super important to me.”

Original story by Bailey Bedford: https://jqi.umd.edu/news/spielman-named-aaas-fellow