Analysis: Science & Technology — 05 November 2026
SLAC X-ray experiment confirms altermagnetism in manganese telluride
A SLAC-led team reports in Science that circularly polarized X-rays at ESRF’s ID32 beamline scatter differently from left- and right-handed polarizations when they strike manganese telluride. That chiral contrast is the signature the authors say was missing for altermagnetism, a magnetic class proposed in 2022. MnTe had been treated as an ordinary antiferromagnet; reproduced 2024–2025 measurements recast it as a distinct phase. The result matters because it supplies a spectroscopic test rather than a list of odd transport effects.
For nearly ninety years, ordered magnetism was split between ferromagnets, whose parallel electron spins produce a net field, and antiferromagnets, whose alternating spins cancel. Altermagnets also alternate spins and show zero net magnetization, but the crystal environments around opposite spins are rotated, breaking a symmetry that conventional antiferromagnets keep. That broken symmetry can support spin-polarized currents while remaining relatively immune to stray fields that scramble ferromagnetic bits.
The chiral X-ray test still leaves room to ask whether other asymmetries could mimic the contrast. On the same news cycle, Oak Ridge neutron diffraction showed that a modest uniaxial squeeze on MnTe and iron sulfide shifts magnetic domain populations and the anomalous Hall effect. Switching by voltage or light, and whether films can be patterned and read at device scale, remain open.
Sources: ScienceDaily; Science (Jost et al.); SLAC; ESRF; Physical Review X; Advanced Materials.
MIT uses flexible polymer ligands to assemble new nanoparticle superlattices
MIT researchers report that highly flexible, electrically charged polymer ligands can organize nanoparticles into crystal structures not previously observed, reversing two decades of preference for rigid molecular connectors. Particle diameter and chain length set how many neighbors each particle binds, yielding more open superlattices instead of dense packing. The work, headed for Nature Materials, treats ligand flexibility as a control knob rather than a defect. It stands out because it does not require custom particle shapes or site-specific surface chemistry.
Nanoparticle superlattices are pursued as designer solids whose properties follow from both the particles and their lattice. Standard methods lock ligands at fixed angles so bonds point in planned directions; those recipes are usually material-specific and hard to scale. Rob Macfarlane’s group lets charged chain ends reorganize until the number of bonds maximizes stability, so valency emerges from flexibility rather than from pre-aimed stickiness.
Independent control of particle identity and lattice type is still incomplete in practice. The study demonstrates new structures, not a working photonic, catalytic, or electronic device. Yield, defect rates, and whether the method survives scale-up beyond laboratory batches are not established.
Sources: ScienceDaily; MIT News; Nature Materials.
ExoMars orbiter ties hydrogen chloride spikes to Alba Mons fissures
ESA’s ExoMars Trace Gas Orbiter has linked localized hydrogen chloride detections to fresh fissures on the northern flanks of Alba Mons, in a Science Advances paper led by Alexander Trokhimovskiy. The gas appears in early northern summer above volcanic rifts, outside the winter dust-and-water cycle that otherwise governs Martian HCl. CaSSIS images show narrow fissures, some hundreds of meters long, with discoloration consistent with vent deposits. The authors interpret the seepage as magmatic gas from a dormant subsurface plumbing system.
TGO first reported HCl in 2021. Mars has the solar system’s largest volcanoes, young-looking lava, and recorded marsquakes, yet no eruption has been seen. The team argues winter ice near −120 °C seals the fissures until sublimation in early summer releases chloride, analogous to terrestrial fumaroles.
Alternative atmospheric chemistry has not been fully ruled out, and the magma chamber is inferred rather than imaged. No lava, heat flow, or isotopic magmatic fingerprint has been measured at the vents. Repeat detections and landed sampling would be needed to confirm ongoing igneous activity.
Sources: Phys.org; ESA; Science Advances.