Research Highlights

Physicists at the National Institute of Standards and Technology (NIST) have linked together, or “entangled,” the mechanical motion and electronic properties of a tiny blue crystal, giving it a quantum edge in measuring electric fields with record sensitivity that may enhance understanding of the universe.

Many physicists use lasers to study quantum mechanics, atomic and molecular physics and nanophysics. While these lasers can be helpful in the research process, there are certain constraints for the researcher. According to JILA Fellow Andreas Becker: "For certain wavelengths of these laser pulses, such as deep ultraviolet, you may not know, or not be able to measure, the temporal profile." The temporal profile of a laser pulse is, however, important for researchers when analyzing data. "A lot of people cannot fully analyze their data, because they don't know the details of the pulse that was used to produce the data," said graduate student Spencer Walker. As a way to research this constraint, the Becker and Jaron-Becker laboratories collaborated to publish a paper in Optics Letters, suggesting a possible solution.

The process of creating spin-polarized electrons has been studied for some time but continues to surprise physicists. These types of electrons have their spin aligned in a specific direction. The probability of creating a spin-polarized electron from an atom tends to be rather small except in some very specific situations. Yet, in a new paper published in Physical Review A, JILA graduate student Spencer Walker, former graduate student Joel Venzke, and former undergraduate student Lucas Kolanz in the Becker Lab theorized a new way towards enhancing this probability through the use of ultrashort laser pulses and an electron’s so-called doorway states. These doorway states are excited states of an electron in an atom that is closest to its lowest energy state, the ground state. 

In a new paper published in Physical Review Letters, JILA and NIST Fellows Eric Cornell, Jun Ye, and Konrad Lehnert developed a method for measuring a potential dark matter candidate, known as an axion-like particle. Axion-like particles are a potential class of dark matter particle which could explain some aspects of galactic structure. This work is also a result of collaboration with Victor Flambaum who is a leading theorist studying possible violations of fundamental symmetries. 

When it comes to galaxies in our universe, there is still much work to do. Part of this work is being done by JILA Fellow and Assistant Professor of Astrophysics, Ann-Marie Madigan, and postdoc Dr. Angela Collier. In a  paper recently published in The Astrophysical Journal, Collier and Madigan postulate that the evolution of a galaxy can be affected by dark matter interacting with the stars within the galaxy. Galaxies evolve over billions of years, changing shape, speed of rotation, and other factors. Studying what affects galaxy evolution is important in answering questions about the foundation of our universe, of how stars and planets are formed, and the origins of dark matter.

Most researchers would agree that it is much easier to write a paper about an observed effect than a paper proving the nonexistence of the effect when it is not observed. NIST JILA Fellow Ralph Jimenez found this to be the case in contributing to a recent paper published in Physical Review Applied. The authors of this paper were originally hoping to observe the increased efficiency in two-photon absorption, a special type of process used in microscopy of living tissue, that had been reported by other research labs. This increased efficiency would be determined by an additional absorption signal than the one being produced by classical light. This additional signal came from using entangled photons. Instead, Jimenez and his team of collaborators from NIST found no additional signal in their measurements, indicating a lack of absorption entirely from the entangled photons. 

The word “quantum” can be mysterious and unfamiliar to the general public. Most of the public’s exposure to quantum technology has been Hollywoodized and framed as a “catch-all” for hard-to-define scientific processes. This misunderstanding causes problems, as quantum technology is quickly being developed and commercialized. With the  “boom” in quantum technology predicted by experts, it is important to realize the repercussions of this misunderstanding. Particularly, writers, scientists, and citizens need to be aware of how to communicate and invoke to the public, an appreciation of the true science of quantum physics. 

The idea of quantum simulation has only become more widely researched in the past few decades. Quantum simulators allow for the study of a quantum system that would be difficult to study easily and quickly in a laboratory or model with a supercomputer. A new paper published in Physical Review Letters, by a collaboration between theorists in the Rey Group and experimentalists in the Thompson laborator,y proposes a way to engineer a quantum simulator of superconductivity that can measure phenomena so far inaccessible in real materials. 

JILA Fellow Jason Dexter works with the Event Horizon Team to further study the first photograph ever taken of a black hole. 

In a significant advance toward the future redefinition of the international unit of time, the second, a research team led by the National Institute of Standards and Technology (NIST) has compared three of the world’s leading atomic clocks with record accuracy over both air and optical fiber links.
 

In a new paper, JILA physicist Thomas Perkins collaborated with CU Biochemistry Prof. Marcello Sousa to dissect the mechanisms of how certain bacteria become more virulent. The research brings together the Perkins lab expertise in single-molecule studies and the Sousa lab expertise in the type III secretion system, a key component of Salmonella bacteria. 

JILA is the host of multiple centers within its campus. Some are National Science Foundation (NSF) funded and others funded by more private centers. Each center focuses on specific topics to advance the knowledge, education, and research on some of the biggest ideas within physics. 
 

Entangled particles have always fascinated physicists, as measuring one entangled particle can result in  a change in another entangled particle, famously dismissed as “spooky action at a distance” by Einstein. By now, physicists understand this strange effect and how to make use of it, for example to increase the sensitivity of measurements. However, entangled states are very fragile, as they can be easily disrupted by decoherence. Researchers have already created entangled states in atoms, photons, electrons and ions, but only recently have studies begun to explore  entanglement in gases of polar molecules. 

When looking within a quantum internet, the Sun Lab is looking at specifically photons. By entangling these photons, scientists tie little quantum knots between them, so they jointly represent the information to be delivered. The photons aren’t just paired off within these quantum knots. They’re connected to hundreds of other photons in a tree-shaped pattern. The robust redundancy of these photons means that scientists can still read the information, even if a few photons are lost.

For nearly a century, scientists have worked to unravel the mystery of dark matter—an elusive substance that spreads through the universe and likely makes up much of its mass, but has so far proven impossible to detect in experiments. Now, a team of researchers have used an innovative technique called “quantum squeezing” to dramatically speed up the search for one candidate for dark matter in the lab. 

For the first time, researchers can turn on an electric field to manipulate molecular interactions, get them to cool down further, and start to explore collective physics where all molecules are coupled to each other.

Building on their newfound ability to induce molecules in ultracold gases to interact with each other over long distances, JILA researchers have used an electric “knob” to influence molecular collisions and dramatically raise or lower chemical reaction rates.

JILA researchers have used a state-of-the-art atomic clock to narrow the search for elusive dark matter, an example of how continual improvements in clocks have value beyond timekeeping.

Follow that electron! JILA researchers have proposed a means of capturing an electron's flight path during ionization, and in doing so, determining the state of the atom at that moment.

When it comes to chemical reactions, shape matters. The Lewandowski Group have studied acetylene and its reactions with propyne and allene to find out how an isomer changes the chemical reaction pathway.