NEWSROOM

A UCLA-led team has extended a quantum phenomenon called the commensurate charge density wave in tantalum disulfide from cryogenic temperatures to roughly 135 F by interleaving layers of the amino acid arginine between ultrathin sheets. Two other amino acids failed to produce the effect, and simulations suggest arginine fits the crystal lattice almost perfectly. The work points to molecule-guided design of quantum materials and possible energy-efficient memory.

Ultrafast light pulses have given physicists fresh evidence on the pseudogap, the enigmatic quantum state that has clouded cuprate superconductors for nearly four decades. Using time- and angle-resolved photoemission spectroscopy, researchers suppressed superconductivity in a copper-based compound and watched the pseudogap appear in its place, then fade as superconductivity returned.

Physicists at Auburn University used laser pulses to bring order to polar nanoregions in a modified strontium titanate crystal, resolving a decades-old debate over whether these charged islands pre-exist or form as atoms shift together. Sensitive optical measurements show the regions are already present before aligning on cooling. Brief light pulses aligned them for about a picosecond, showing light can both create and read the pattern.

Cornell researchers found that applying voltage to a four-layer graphene stack slides the layers between atomic stacking arrangements, reversibly switching the material between nonmagnetic and magnetic states. The effect, reported in Nature Nanotechnology, exploits weak van der Waals bonds rather than breaking chemical bonds, and the resulting state persists after voltage is removed.

Two new studies catalog nearly 9,000 two-dimensional materials and identify 61 semimetals and 1,568 insulators suited to twistronics, the stacking and rotating of atomically thin layers to engineer narrow electronic bands. The work maps topological electronic structures, predicts promising twisted bilayers such as tin diselenide and hafnium disulfide, and confirms several candidates can be grown in bulk and exfoliated into working devices, giving researchers a systematic rout

Researchers at the University of Osaka have directly observed a heavy-fermion state forming at the interface between a one-atom-thick ytterbium-copper (YbCu₂) layer and a copper crystal, using intense synchrotron light to probe electron behavior. They identified two distinct states, one confined to the two-dimensional layer and another extending into the three-dimensional substrate, arising from hybridization between localized Yb 4f and mobile conduction electrons.