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Scientists have found a new way to create disturbances that do not fade away. Instead of relying on disorder to freeze things in place, they tipped a quantum container to one side—a trick that is easier to conjure in the lab. A collaboration between the experimental group of College Park Professor Christopher Monroe and the theoretical group of JQI Fellow Alexey Gorshkov, who is also a Fellow of the Joint Center for Quantum Information and Computer Science, has used trapped ions to implement this new technique, confirming that it prevents their quantum particles from reaching equilibrium. The team also measured the slowed spread of information with the new tipping technique for the first time. They published their results recently in the journal Nature.

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.

We all know that diamonds can hold great sentimental (and monetary) value. As luck may have it, diamonds—particularly defective ones, with little errors in their crystal structure—also hold great scientific value. The defects have properties that can only be described by quantum mechanics, and researchers are working on harnessing these properties to pick up on tiny signals coming from individual biological cells. In this episode of Relatively Certain, Dina sits down with defective diamond expert Ronald Walsworth, the founding director of the Quantum Technology Center at the University of Maryland (UMD), as well as Minta Martin professor of electrical and computer engineering and professor of physics at the UMD. Walsworth is also a member of the Institute for Research in Electronics & Applied Physics and a Fellow of the Joint Quantum Institute. Walsworth explains how diamond defects can be used as superb magnetic field sensors and discusses recent strides toward using them to image the insides of individual cells. More details on these advances can be found in two recent publications from Walsworth’s lab. This episode of Relatively Certain was produced by Dina Genkina, Chris Cesare and Emily Edwards. Music featured in this episode includes Picturebook by Dave Depper, The Jitters and Apogee by Metre and Examples by Ketsa, with sound effects by Brian Little. Relatively Certain is a production of the Joint Quantum Institute, a research partnership between the University of Maryland and the National Institute of Standards and Technology, and you can find it on iTunes, Google Play, Soundcloud or Spotify.

On the cover of the Pink Floyd album Dark Side of the Moon, a prism splits a ray of light into all the colors of the rainbow. This multicolored medley, which owes its emergence to the fact that light travels as a wave, is almost always hiding in plain sight; a prism simply reveals that it was there. For instance, sunlight is a mixture of many different colors of light, each bobbing up and down with their own characteristic frequency. But taken together the colors merge into a uniform yellowish glow. A prism, or something like it, can also undo this splitting, mixing a rainbow back into a single beam. Back in the late 1970s, scientists figured out how to generate many colors of light, evenly spaced in frequency, and mix them together—a creation that became known as a frequency comb because of the spiky way the frequencies lined up like the teeth on a comb. They also overlapped the crests of the different frequencies in one spot, making the colors come together to form short pulses of light rather than one continuous beam. As frequency comb technology developed, scientists realized that they could enable new laboratory developments, such as ultra-precise optical atomic clocks, and by 2005 frequency combs had earned two scientists a share of the Nobel Prize in physics. These days, frequency combs are finding uses in modern technology, by helping self-driving cars to “see” and allowing optical fibers to transmit many channels worth of information at once, among others. Now, a collaboration of researchers at the University of Maryland (UMD) has proposed a way to make chip-sized frequency combs ten times more efficient by harnessing the power of topology—a field of abstract math that underlies some of the most peculiar behaviors of modern materials. The team, led by JQI Fellows Mohammad Hafezi and Kartik Srinivasan, as well as Yanne Chembo, an associate professor of electrical and computer engineering at UMD and a member of the Institute for Research in Electronics and Applied Physics, published their result recently in the journal Nature Physics.