Beyond Majorana: Ultracold gases as a platform for observing exotic robust quantum states

The quantum Hall effect, discovered in the early 1980s, is a phenomenon that was observed in a two-dimensional gas of electrons existing at the interface between two semiconductor layers. Subject to the severe criteria of very high material purity and very low temperatures, the electrons, when under the influence of a large magnetic field, will organize themselves into an ensemble state featuring remarkable properties.

Many physicists believe that quantum Hall physics is not unique to electrons, and thus it should be possible to observe this behavior elsewhere, such as in a collection of trapped ultracold atoms. Experiments at JQI and elsewhere are being planned to do just that. On the theoretical front, scientists* at JQI and University of Maryland have also made progress, which they describe in the journal Physical Review Letters. The result, to be summarized here, proposes using quantum matter made from a neutral atomic gas, instead of electrons. In this new design, elusive exotic states that are predicted to occur in certain quantum Hall systems should emerge. These states, known as parafermionic zero modes, may be useful in building robust quantum gates.

 

Physicists Show ‘Molecules’ Made of Light May Be Possible

It’s not lightsaber time, not yet. But a team including theoretical physicists from JQI and NIST has taken another step toward building objects out of photons, and the findings hint that weightless particles of light can be joined into a sort of “molecule” with its own peculiar force. Researchers show that two photons, depicted in this artist’s conception as waves (left and right), can be locked together at a short distance. Under certain conditions, the photons can form a state resembling a two-atom molecule, represented as the blue dumbbell shape at center.

The findings build on previous research that several team members contributed to before joining JQI and NIST. In 2013, collaborators from Harvard, Caltech and MIT found a way to bind two photons together so that one would sit right atop the other, superimposed as they travel. Their experimental demonstration was considered a breakthrough, because no one had ever constructed anything by combining individual photons—inspiring some to imagine that real-life lightsabers were just around the corner.

See more at: http://jqi.umd.edu/news/jqi-physicists-show-molecules-made-light-may-be-possible#sthash.FlERjh1d.dpuf

David Buehrle Named Merrill Mentor

Senior Lecturer David Buehrle has been named a Faculty Mentor for Merrill Presidential Scholar Julia Waigner. The Merrill program honors the University of Maryland’s most successful seniors and their designated University faculty and K-12 teachers for their mentorship. Merrill Scholars and their mentors will be honored in a special ceremony on November 13.

Julia wrote that "David Buehrle took Physics II, a subject I feared, and turned it into one of my all-time favorite classes. Prof. Buerhle does an excellent job framing physical concepts in a biological light. He is approachable and always available for my questions, regardless of how relevant they were to coursework. Not only did he teach me physics, he taught me an entirely new and integrative way to think about the sciences."

http://www.ugst.umd.edu/merrill/scholarsmpsp.html#yeh​

Jay Sau Awarded the 2015 Richard A. Ferrell Distinguished Faculty Fellowship

Jay Sau has received the 2015 Richard A. Ferrell Distinguished Faculty Fellowship, which recognizes outstanding personal effort and expertise in physics as well as dedicated service to the UMD Department of Physics. The Fellowship, established in 2001, honors Dr. Richard A. Ferrell, a deeply-respected physicist who joined the University in 1953, served 40 years, and remained active in the department even after his retirement. Dr. Ferrell died in 2005 at his nearby University Park home.

Sau is an Assistant Professor researching topics including Majorana fermions and topological superconductivity, quantum non-abelian phases and topological quantum computation, and spin-orbit coupling and dynamics in cold atomic gases. He is a fellow of the Joint Quantum Institute and a member of the Condensed Matter Theory Center.