Twisting Up Atoms Through Space and Time

One of the most exciting applications of quantum computers will be to direct their gaze inwards, at the very quantum rules that make them tick. Quantum computers can be used to simulate quantum physics itself, and perhaps even explore realms that don’t exist anywhere in nature. But even in the absence of a fully functional, large-scale quantum computer, physicists can use a quantum system they can easily control to emulate a more complicated or less accessible one. Now, researchers have coached their ultracold atoms to do a new dance, adding to the growing toolkit of quantum simulation.

Electrons Take New Shape Inside Unconventional Metal

One of the biggest achievements of quantum physics was recasting our vision of the atom. Out was the early 1900s model of a solar system in miniature. Instead, quantum physics showed that electrons meander around the nucleus in clouds that look like tiny balloons. These balloons are known as atomic orbitals, and they come in all sorts of different shapes—perfectly round, two-lobed, clover-leaf-shaped. That’s all well and good for individual atoms, but when atoms come together to form something solid—like a chunk of metal, say—the outermost electrons in the atoms link arms and lose sight of the nucleus they came from, forming many oversized balloons that span the whole chunk of metal. Now, researchers have produced the first experimental evidence that one metal—and likely others in its class—have electrons that manage to preserve a more interesting, multi-lobed structure as they move around in a solid.

Unveiling the Universe: In 4 New Studies, NIST Explores Novel Ways to Hunt Dark Matter

Scientists have been searching for dark matter with no success for more than 30 years. JQI and other NIST researchers are now exploring new ways to search for the invisible particles. In one study, a prototype for a much larger experiment, researchers have used state-of-the-art superconducting detectors to hunt for dark matter. The study has already placed new limits on the possible mass of one type of hypothesized dark matter. Another NIST team has proposed that trapped electrons, commonly used to measure properties of ordinary particles, could also serve as highly sensitive detectors of hypothetical dark matter particles if they carry charge.

Graphs May Prove Key in Search for Holy Grail of Quantum Error Correction

In February 2019, JQI Fellow Alicia Kollár, who is also an assistant professor of physics at UMD, bumped into Adrian Chapman, then a postdoctoral fellow at the University of Sydney, at a quantum information conference. Although the two came from very different scientific backgrounds, they quickly discovered that their research had a surprising commonality. They both shared an interest in graph theory, a field of math that deals with points and the connections between them. Their ensuing collaboration resulted in a new tool that aids in the search for new quantum error correction schemes—including the Holy Grail of self-correcting quantum error correction. They published their findings recently in the journal Physical Review X Quantum.

Quantum Gases Keep Their Cool, Prompting New Mysteries

Quantum physics is a notorious rule-breaker. For example, it makes the classical laws of thermodynamics, which describe how heat and energy move around, look more like guidelines than ironclad natural laws. In some experiments, a quantum object can keep its cool despite sitting next to something hot that is steadily releasing energy. A new experiment led by David Weld, an associate professor of physics at the University of California, Santa Barbra (UCSB), in collaboration with JQI Fellow Victor Galitski, shows that several interacting quantum particles can also keep their cool—at least for a time.