graphene

Physicists sometimes come up with crazy stories that sound like science fiction. Some turn out to be true, like how the curvature of space and time described by Einstein was eventually borne out by astronomical measurements. Others linger on as mere possibilities or mathematical curiosities. In a new paper in Physical Review Research, JQI Fellow Victor Galitski and JQI graduate student Alireza Parhizkar have explored the imaginative possibility that our reality is only one half of a pair of interacting worlds. Their mathematical model may provide a new perspective for looking at fundamental features of reality—including why our universe expands the way it does and how that relates to the most miniscule lengths allowed in quantum mechanics. These topics are crucial to understanding our universe and are part of one of the great mysteries of modern physics.

Atomically thin sheets of carbon, called graphene, have caught many scientists' attention in recent years. Researchers have discovered that stacking layers of graphene two or three at a time and twisting the layers opens fertile new territory for them to explore. Research into these stacked sheets of graphene is like the Wild West, complete with the lure of striking gold and the uncertainty of uncharted territory. Researchers at JQI and the Condensed Matter Theory Center (CMTC) at the University of Maryland are busy creating the theoretical physics foundation that will be a map of this new landscape. And there is a lot to map; the phenomena in graphene range from the familiar like magnetism to more exotic things like strange metallicity, different versions of the quantum Hall effect, and the Pomeranchuk effect—each of which involve electrons coordinating to produce unique behaviors. One of the most promising veins for scientific treasure is the appearance of superconductivity (lossless electrical flow) in stacked graphene.

JQI group uses diamond-based quantum sensors produce images of currents in graphene.

A team of researchers has devised a simple way to tune a hallmark quantum effect in graphene—the material formed from a single layer of carbon atoms—by bathing it in light. Their theoretical work, which was published recently in Physical Review Letters, suggests a way to realize novel quantum behavior that was previously predicted but has so far remained inaccessible in experiments.