In recent years, atomically thin materials—crystals only a few atoms thick—have attracted growing attention because they can exhibit physical properties that do not appear in conventional bulk materials. Among them, atomically thin magnetic materials are particularly intriguing, as they can host unconventional magnetic states and offer new possibilities for spin-based electronic technologies.

In a Nature Materials study, researchers investigated the photocurrent response of a bilayer atomically thin antiferromagnet. In this material, spins are aligned within each atomic layer, while the spin orientations of the top and bottom layers are opposite. Depending on the relative spin configuration between the two layers, the system exhibits two distinct antiferromagnetic (AFM) states.

To explore how these magnetic states interact with light, the researchers fabricated devices by attaching electrodes to bilayer samples and illuminated the center of the material, away from the electrodes. They measured both the zero-bias photocurrent and current-voltage characteristics under illumination.

New density-functional-theory calculations describe the radioactive decay of tritium bound to graphene, offering a way to model experiments that could open cleaner windows onto neutrino mass.

The discovery that neutrinos oscillate—shifting among three “flavors” (electron, muon, and tau) as they propagate—showed that these elusive particles must have mass. Yet their absolute mass scale and the mass ordering (whether the lightest neutrino state is predominantly electron-, muon-, or tau-like) remain unknown. Determining these properties is a central goal of modern particle physics. A promising approach involves measuring the energy spectrum of electrons emitted in nuclear decay, particularly from tritium: Because the neutrino carries away part of the decay energy, a nonzero neutrino mass slightly modifies the spectrum of emitted electrons. Precision experiments such as KATRIN have pushed this method to its limit, setting an upper bound of about 0.45 eV on the neutrino mass [1]. While KATRIN uses molecular tritium gas, new strategies aim to go further by embedding tritium in engineered materials.