Catálogo de publicaciones - revistas

<jats:title>Restoring strangeness</jats:title> <jats:p> Cuprate superconductors host a number of complex phases, and elucidating their relationship to each other may shed light on the nature of cuprate superconductivity. Two of these intriguing phases are the strange metal phase and the charge-density wave (CDW) order, which appear next to each other in the cuprate phase diagram. The hallmark of the strange metal phase, the linear dependence of electrical resistivity on temperature, disappears in the CDW phase. Wahlberg <jats:italic>et al</jats:italic> . strained thin films of the cuprate YBa <jats:sub>2</jats:sub> Cu <jats:sub>3</jats:sub> O <jats:sub>7–δ</jats:sub> to suppress CDW order (see the Perspective by Le Tacon). Using resonant inelastic x-ray scattering and transport measurements, the researchers found that suppressing CDW restored the linear-in-temperature resistivity in the CDW portion of the phase diagram. —JS </jats:p>

<jats:title>Quantum trapping and shuffling</jats:title> <jats:p> Programmable arrays of atoms or ions trapped in optical potentials have recently emerged as a leading platform for quantum simulation. Being able to interface into these arrays to access the quantum information being processed and pass it along to another module remains a challenge. Ðorđević <jats:italic>et al</jats:italic> . developed a hybrid quantum system that combines atoms held in optical tweezers and a nanophotonic cavity to demonstrate full quantum control, efficient quantum nondestructive readout, and entanglement of atom pairs (see the Perspective by Kaufman). By combining atomic manipulation both inside and away from the cavity field and shuffling the atom qubits into and out of the cavity mode, the authors demonstrate a viable optical interface that could be scaled to larger systems. —ISO </jats:p>

<jats:title>Topologically locked for emission</jats:title> <jats:p> The output power from a laser system can be increased by forming an array of lasers; however, because the individual lasers are independent, the resultant output may not be coherent. Dikopoltsev <jats:italic>et al</jats:italic> . report on the realization of a topological vertical-cavity surface-emitting laser (VCSEL) array. The topological nature of the array-based laser emission was achieved through a combination of topological in-plane propagation of evanescent light linking the vertical cavity surface-emitting lasers of the array. The topological features of the array force injection locking, making all emitters (30 in this case) act as a single coherent laser. This development will be important for realizing large-scale coherent laser arrays. —ISO </jats:p>

<jats:title>Going with the grain</jats:title> <jats:p> Changes in surface structure can make metal nanoparticles supported on oxides more active for certain catalytic reactions. Huang <jats:italic>et al</jats:italic> . show that steam pretreatment of palladium nanoparticles on alumina led to a high density of twin boundaries, unlike other oxidation and reduction pretreatments. The density of these stable grain boundaries at the surface correlated with higher methane oxidation rates and lower temperatures for the initiation of the reaction. The introduction of additional defect sites through laser ablation created even more active catalysts. —PDS </jats:p>

<jats:title>From carbon dioxide to starch: no plants required</jats:title> <jats:p> Many plants turn glucose from photosynthesis into polymers that form insoluble starch granules ideal for long-term energy storage in roots and seeds. Cai <jats:italic>et al</jats:italic> . developed a hybrid system in which carbon dioxide is reduced to methanol by an inorganic catalyst and then converted by enzymes first to three and six carbon sugar units and then to polymeric starch. This artificial starch anabolic pathway relies on engineered recombinant enzymes from many different source organisms and can be tuned to produce amylose or amylopectin at excellent rates and efficiencies relative to other synthetic carbon fixation systems—and, depending on the metric used, even to field crops. —MAF </jats:p>

<jats:title>Early footsteps in the Americas</jats:title> <jats:p> Despite a plethora of archaeological research over the past century, the timing of human migration into the Americas is still far from resolved. In a study of exposed outcrops of Lake Otero in White Sands National Park in New Mexico, Bennett <jats:italic>et al</jats:italic> . reveal numerous human footprints dating to about 23,000 to 21,000 years ago. These finds indicate the presence of humans in North America for approximately two millennia during the Last Glacial Maximum south of the migratory barrier created by the ice sheets to the north. This timing coincided with a Northern Hemispheric abrupt warming event, Dansgaard-Oeschger event 2, which drew down lake levels and allowed humans and megafauna to walk on newly exposed surfaces, creating tracks that became preserved in the geologic record. —AMS </jats:p>

<jats:title>Building a wider root network</jats:title> <jats:p> As roots grow through the soil, lateral branches develop to broaden the reach toward water and nutrients. Just where on the main root these lateral roots will develop is organized by an oscillatory root clock. Dickinson <jats:italic>et al</jats:italic> . have now identified an initiating signal in the form of the signaling molecule retinal. Oscillatory expression of a retinal-binding protein, a temperature-sensitive lipocalin, defines sites where retinal signals can initiate growth. —PJH </jats:p>

<jats:title>Pluripotency factor drives cardiogenesis</jats:title> <jats:p> Research indicates that the adult mammalian heart does not contain cardiac stem cells and the vast majority of cardiomyocytes do not divide. Heart regeneration is thus limited after injury. The postmitotic nature of cardiomyocytes blocks cardiac tumor formation but at the same time minimizes cardiomyocyte renewal. Chen <jats:italic>et al</jats:italic> . report that cell type–specific expression of pluripotency factors dedifferentiates adult cardiomyocytes to a state that resembles fetal cardiomyocytes, enabling adult cardiomyocytes to reenter mitosis (see the Perspective by Wang and Blau). Cardiomyocytes can be reprogrammed to a pluripotent state when expression of pluripotency factors is sustained over an extended period. If cardiomyocytes are only partially reprogrammed, the heart regenerates without tumor formation. —BAP </jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>