An emerging frontier in condensed matter physics involves novel electromagnetic responses, such as the anomalous Hall effect (AHE), in ferromagnetic Weyl semimetals (FM-WSMs). Candidate FM-WSMs have been limited to materials that preserve inversion symmetry and generate Weyl crossings by breaking the time-reversal symmetry. These materials share three common features: a centrosymmetric lattice, a collinear FM ordering, and a large AHE observed when the field is parallel to the magnetic easy axis. Here we present CeAlSi as a FM-WSM in which the Weyl nodes are stabilized by breaking the inversion symmetry, but their positions are tuned by breaking the time-reversal symmetry. Unlike the other FM-WSMs, CeAlSi has a noncentrosymmetric lattice, a noncollinear FM ordering, and a novel AHE that is anisotropic between the easy and hard magnetic axes. It also exhibits large FM domains that are promising for exploring both device applications and the interplay between the Weyl nodes and FM domain walls.

Phonons are known to generate a thermal Hall effect in certain insulators, including oxides with rare-earth impurities, quantum paraelectrics, multiferroic materials, and cuprate Mott insulators. In each case, a special feature of the material is presumed relevant for the underlying mechanism that confers chirality to phonons in a magnetic field. A fundamental question is whether a phonon Hall effect is an unusual occurrence—linked to special characteristics such as skew scattering off rare-earth impurities, structural domains, ferroelectricity, or ferromagnetism—or a much more common property of insulators than hitherto believed. To help answer this question, we have turned to a material with none of the previously encountered special features: the cubic antiferromagnet Cu₃TeO₆. We find that its thermal Hall conductivityκxyis among the largest of any insulator so far. We show that this record-highκxysignal is due to phonons, and it does not require the presence of magnetic order, as it persists above the ordering temperature. We conclude that the phonon Hall effect is likely to be a fairly common property of solids.

Kitaev magnets are materials with bond-dependent Ising interactions between localized spins on a honeycomb lattice. Such interactions could lead to a quantum spin-liquid (QSL) ground state at zero temperature. Recent theoretical studies suggest two potential signatures of a QSL at finite temperatures, namely, a scaling behavior of thermodynamic quantities in the presence of quenched disorder, and a two-step release of the magnetic entropy. Here, we present both signatures in ${\mathrm{Ag}}_3{\mathrm{LiIr}}_2{\mathrm{O}}_6$ which is synthesized from $\alpha \text{−}{\mathrm{Li}}_2{\mathrm{IrO}}_3$ by replacing the interlayer Li atoms with Ag atoms. In addition, the dc susceptibility data confirm the absence of a long-range order, and the ac susceptibility data rule out a spin-glass transition. These observations suggest a closer proximity to the QSL in ${\mathrm{Ag}}_3{\mathrm{LiIr}}_2{\mathrm{O}}_6$ compared to its parent compound $\alpha \text{−}{\mathrm{Li}}_2{\mathrm{IrO}}_3$ that orders at 15 K. We discuss an enhanced spin-orbit coupling due to a mixing between silver $d$ and oxygen $p$ orbitals as a potential underlying mechanism.