Science Highlights

In a pair of publications, researchers investigated how different species of microbes interact with one another and exchange resources such as vitamins. The studies focused on corrinoids, the vitamin B12 family of nutrients. Many bacteria in the environment cannot produce these chemicals. The studies demonstrated that the presence of corrinoids can influence how individual soil bacteria grow in the laboratory and how they survive and coexist in soil.

Inside a neutron star, protons and electrons combine into uncharged neutron matter. Researchers have now calculated spin and density correlations in neutron matter using realistic nuclear interactions at higher densities of neutrons than previously explored. They also developed a new algorithm that greatly reduces the computational effort needed to calculate observables involving multiple particles.

Copper is a promising catalyst for converting carbon dioxide into reduced species, a step in converting carbon dioxide into fuels. Although often initiated by electrical energy, this reaction can also be achieved using solar energy. In this work, scientists used X-rays to investigate how copper catalysts change when operating only with light and no applied electricity. The work found that the copper plays an unexpected role, producing an oxidized, not reduced, species.

Researchers at the Facility for Rare Isotope Beams made a high-precision mass measurement of aluminum-22, reaching the “proton dripline” of the nuclear chart. The project found that aluminum-22 formed a proton halo, where the last proton added is only loosely bound to the nucleus. This measurement helps scientists determine how tightly bound the atomic nuclei are as they get closer to the dripline.

Entangled quantum bits per second (ebps) indicates a quantum network’s throughput. In this study, researchers collected ebps measurements over a suite of fiber connections on a quantum network testbed. They then compared these measurements with capacity estimates for a conventional fiber-optic network at a range of distances. The study finds that ebps throughput decays sharply with distance in ways that differ from conventional networks.

For the first time, scientists can distinguish the proportion of bromoform molecules that directly break bonds (dissociate) vs. those that rearrange (isomerize). This is an important step toward understanding the formation of bromoform isomers, which had long been predicted but had not been fully experimentally confirmed. Bromoform molecules are important in part for their role in ozone degradation in the Earth’s atmosphere. 

The trace anomaly is one of the quantities that encodes the energy and momentum of particles built from quarks. Scientists believe the trace anomaly is crucial for keeping quarks bonded in subatomic particles. In this study, scientists calculated the trace anomaly for nucleons and pions. The calculations show that in the pion, the mass distribution is similar to the charge distribution of the neutron and in the nucleon, the mass distribution is similar to the charge distribution of the proton.

The behavior of catalysts that promote chemical reactions is not always straightforward. Using a combination of experiments and computer simulations, scientists now understand how oxygen affects the way the catalyst copper oxide reacts with hydrogen versus carbon monoxide gases and how to control and enhance related chemical reactions.