• Sharp first-order structural transition to rhombohedral R-3 with strong thermal hysteresis.
• Spherical and longitudinal neutron polarization analysis used to determine full 3D magnetic moment orientation.
• Ru3+ moments in the zigzag phase tilt ≈ 15.7° out of plane and exhibit an in-plane twist of ≈ −13.8°.
• Resulting magnetic geometry conflicts with prior unpolarized neutron and REXS-based models, affecting microscopic parameter inferences.

Using unpolarized and polarized neutron diffraction on high-quality single crystals, the authors reexamine the low-temperature crystal and magnetic structures of α-RuCl3 and confirm a sharp first-order transition into an R-3 rhombohedral structure. Polarization analysis allows them to fix the three-dimensional orientation of the ordered Ru3+ moments, which are found to cant about 15.7 degrees out of the honeycomb plane and to carry an extra in-plane rotation of roughly −13.8 degrees. This combined tilt-and-twist configuration departs from earlier descriptions based on unpolarized neutron or REXS data and has implications for microscopic Hamiltonians used to model proximate Kitaev physics.

• Two long-period superlattices observed, featuring harmonic and anharmonic structural modulations.
• Interlayer bonds modulate in a sublattice-selective pattern that enforces a kagome zero-sum constraint.
• Combination of synchrotron XRD, real-space TEM, and model calculations supports bond-density-wave interpretation.
• Findings show chemical bonding as an additional route to frustration-driven ordering in kagome metals, persisting above room temperature.

The authors report bond-density-wave ordering in the kagome metal CeRu3Si2 observed above room temperature. Using synchrotron X-ray diffraction, transmission electron microscopy, and theoretical modeling, they identify two distinct long-period superlattices with both harmonic and anharmonic modulations, where interlayer bonds between kagome planes modulate selectively on sublattices to satisfy a local zero-sum constraint. The work demonstrates that chemical bonding can generate frustration-constrained bond order in kagome metals, expanding the set of emergent phases associated with geometric frustration.

• Programmable realization of dipolar square spin ice on a superconducting-qubit quantum annealer with >400 vertices.
• Direct mapping between qubits and lattice spins plus engineered extended couplings realize effective dipolar interactions.
• Tunable transverse field allows probing of real-time dynamics of Dirac strings and monopole plasmas.
• Observed super-diffusive monopole transport with scaling exponents between diffusion and ballistic, indicative of quantum-coherent effects.

The authors implement a dipolar square spin-ice model on a superconducting-qubit quantum annealer by mapping physical qubits one-to-one to lattice spins and engineering extended couplings across more than 400 vertices. Varying transverse-field fluctuations exposes real-time dynamics of Dirac-string defects and interacting monopole plasmas; the observed monopole transport is super-diffusive, with scaling exponents between classical diffusion and ballistic motion. These results indicate dynamics beyond classical stochastic relaxation and suggest coherent propagation of fractionalized excitations in a controllable, scalable platform for studying quantum spin-ice physics.

• Programmable two-plane kagome spin ice implemented on a D-Wave Advantage2 device with 1,536 logical spins.
• Interlayer coupling drives a sharp ferroelectric-to-antiferroelectric transition into an Ice-II phase at (J_perp/J1)* ≈ 0.044.
• Plaquette-restricted charge structure factor reveals a much stronger Ice-II signal than conventional estimators.
• Quantum renormalization of the monopole chemical potential is quantified and practical predictions for nanowire bilayers are provided.

Using the native architecture of a D-Wave Advantage2 quantum annealer, the author programs a bilayer kagome spin-ice spanning 1,536 logical spins and explores system size, interlayer coupling, and quantum drive. Interlayer exchange produces a sharp transition from a ferroelectric to an antiferroelectric staggered charge order (an Ice-II phase) with a critical coupling ratio near 0.044 that remains stable across many annealing times. The study also introduces a plaquette-restricted structure factor estimator that greatly enhances the Ice-II signal, identifies quantum renormalization of the monopole chemical potential, and offers three testable predictions for existing Ni81Fe19 nanowire bilayer systems.

• Model studied: antiferromagnetic Ising model on icosahedral bcc lattice (1/1 Tsai approximant).
• Numerical method: Monte Carlo with parallel tempering to ensure equilibration.
• A second-order phase transition occurs to a phase with Z3 × Z2 symmetry breaking.
• Low-temperature phase retains finite residual entropy (~0.1767 per spin) and suppresses domain walls, producing entropic crystallization.

The study investigates the antiferromagnetic Ising model on the icosahedral bcc lattice as a 1/1 Tsai-type quasicrystal approximant using Markov-chain Monte Carlo with parallel tempering. They find a second-order transition into a magnetically ordered state that breaks Z3 × Z2 symmetry while still maintaining a macroscopically large residual entropy of about 0.1767 per spin. The authors argue that residual entropy suppresses domain-wall formation because walls locally reduce the stored entropy, so the magnetic ordering is entropy-driven — an entropic crystallization mechanism relevant to strongly frustrated systems with large geometric units.