We propose to realize the quantum anomalous Hall effect (QAHE) in two-dimensional compensated antiferromagnets without net spin magnetization. We consider antiferromagnetic ${\mathrm{MnBi}}_2{\mathrm{Te}}_4$ as a concrete example. By breaking the parity-time ($\mathcal{P}\mathcal{T}$) symmetry of even-layer ${\mathrm{MnBi}}_2{\mathrm{Te}}_4$, we find that the system can host the QAHE with a nonzero Chern number. We show that by controlling the antiferromagnetic spin configuration—for example, down/up/up/down that breaks $\mathcal{P}\mathcal{T}$ symmetry—tetralayer ${\mathrm{MnBi}}_2{\mathrm{Te}}_4$ can host a Chern number $|\mathcal{C}|=1$. Such spin configuration can be stabilized by pinning the spin orientations of the surfaces. Furthermore, via tuning the on-site orbital energy and vertical electric fields, we find rich QAHE phases with tunable Chern number of $|\mathcal{C}|=1,2,3$. In addition, we reveal that the edge states are layer selective and primarily located at the boundaries of the bottom and top layers. Our Letter not only proposes a scheme to realize Chern number tunable QAHE in antiferromagnets without net spin magnetization but also provides a platform for layer-selective dissipationless transport devices.

Landau levels play a fundamental role in condensed matter physics, as they offer critical insights into charged particles’ behavior in magnetic fields. These unique characteristics have significant implications for understanding various quantum phenomena and materials’ electronic properties, such as the renowned quantum Hall effect. Over the past two decades, substantial advancements have been achieved in Landau levels in systems with linear band crossing points, like Weyl points, which exhibit fascinating features like chiral zero modes. The Landau levels observed thus far are independent of the magnetic field’s orientation. In this Letter, we experimentally demonstrate unconventional oriented Landau levels in acoustic Berry dipole systems, wherein by reversing the orientation of the pseudomagnetic field, the system exhibits distinct Landau spectra. Remarkably, we observe a new type of helical zero mode, whose existence critically depends on the magnetic field’s orientation. This is in sharp contrast to the well-studied chiral zero modes in Weyl systems, whose propagation direction, but not existence, depends on the applied magnetic field’s orientation. Our Letter opens up avenues for understanding the interaction of gauge fields with band singularities that go beyond Chern class, including Berry multipoles and even-dimensional monopoles, and offers new insights for exploring topological devices.

Topological phases of matter provide a flexible platform to engineer unconventional quantum excitations in quantum materials. Beyond single particle topological matter, in systems with strong quantum many-body correlations, many-body effects can be the driving force for non-trivial topology. Here, we propose a one-dimensional engineered Kondo lattice where the emergence of topological excitations is driven by collective many-body Kondo physics. We first show the existence of topological zero modes in this system by solving the interacting model with tensor networks, and demonstrate their robustness against disorder. To unveil the origin of the topological zero modes, we analyze the associated periodic Anderson model showing that it can be mapped to a topological non-Hermitian model, enabling rationalizing the origin of the topological zero modes. We finally show that the topological invariant of the many-body Kondo lattice can be computed with a correlation matrix pumping method directly with the exact quantum many-body wave function. Our results provide a strategy to engineer topological Kondo insulators, highlighting quantum magnetism as a driving force in engineering topological matter.

Uniaxial magnetocrystalline anisotropy (UMA) is the foundation for data storage technology as well as for realizing topological and quantum phases. Combined with the confined electrons and distinct lattice dynamics of two-dimensional (2D) materials, exploring UMA, especially its temperature dependence in 2D ferromagnets, is significant. Here, we report an unprecedented exotic behavior of temperature dependence of UMA in the 2D van der Waals ferromagnet ${\mathrm{Fe}}_3{\mathrm{GeTe}}_2$. Below 20 K, the temperature-dependent UMA constant $K_{\mathrm{u}1}(T)$ exhibits a canonical Akulov-Zener-Callen-Callen-type $K_{\mathrm{u}1}(T)$ with rapidly decreasing trend. Strikingly, above 20 K, it transitions to an anomalous Carr-type one with rapidly increasing trend. Temperature-dependent x-ray diffraction measurements combined with first-principles calculations reveal that the enhanced ferromagnetic exchange coupling caused by the lattice variation preserves the two-ion anisotropy at high temperature. Therein, both the itinerant nature and lattice thermal expansion are altered, thus triggering such exotic $K_{\mathrm{u}1}(T)$. Our findings not only deepen the basic understanding of the temperature dependence of UMA but also favor optimizing the ultra-high-density heat-assisted magnetic recording technology by considering the cooperation between lattice and ferromagnetic exchange coupling.

Antiferromagnetic spintronics has long been a subject of intense research interest, and the recent introduction of altermagnetism has further ignited enthusiasm in the field. However, fully compensated ferrimagnetism, which exhibits band spin splitting but zero net magnetization, has yet to receive enough attention. Since the experimental preparation of two-dimensional (2D) magnetic van der Waals (vdW) materials in 2017, 2D magnetic materials, thanks to their super tunability, have quickly become an important playground for spintronics. Here, we extend the concept of fully compensated ferrimagnetism (fFIM) to two dimensions and propose 2D filling-enforced fFIM, demonstrate its stability and ease of manipulation, and present three feasible realization schemes with respective exemplary candidate materials. A simple model for 2D fully compensated ferrimagnets (fFIMs) is developed. Further investigation of 2D fFIMs’ physical properties reveals that they not only exhibit significant magneto-optical response but also show fully spin-polarized currents and the anomalous Hall effect in the half-metallic states, displaying characteristics previously almost exclusive to ferromagnetic materials, greatly broadening the research and application prospects of spintronic materials.

Charged colloids can form ordered structures like Wigner crystals or glasses at very low concentrations due to long-range electrostatic repulsions. Here, we combine small-angle x-ray scattering (SAXS) and optical experiments with simulations to investigate the phase behavior of charged rodlike colloids across a wide range of salt concentrations and packing fractions. At ultralow ionic strength and packing fractions, we reveal both experimentally and numerically a direct transition from a nematic to a crystalline smectic-B phase, previously identified as a glass state. This transition, bypassing the smectic-A intermediate phase, results from minimizing Coulomb repulsion and maximizing entropic gains due to fluctuations in the crystalline structure. This demonstrates how long-range electrostatic repulsion significantly alters the phase behavior of rod-shaped particles and highlights its key role in driving the self-organization of anisotropic particles.

Symmetry-protected topological phases (SPTs) characterized by short-range entanglement include many states essential to the understanding of topological condensed matter physics, and the extension to gapless SPTs provides essential understanding of their consequences. In this work, we identify a fundamental connection between gapless SPTs and recently introduced multiplicative topological phases, demonstrating that multiplicative topological phases are an intuitive and general approach to realizing concrete models for gapless SPTs. In particular, they are naturally well suited to realizing higher-dimensional, stable, and intrinsically gapless SPTs through the combination of canonical topological insulator and semimetal models with critical gapless models in symmetry-protected tensor product constructions, opening avenues to far broader and deeper investigation of topology via short-range entanglement.

The altermagnetic nature of a large class of magnetically ordered materials is the source of a wide range of new effects. Here, we show that the merging of two areas, namely the altermagnetism and the physics of curvilinear low-dimensional magnets gives rise to a distinct novel physical effect: a curvature-induced magnetization in bend altermagnetic films. This effect opens a promising possibility for imaging of the domain structure in the magnetically compensated structures. We consider a thin film of a $d$-wave altermagnet bent in a stretching-free manner and demonstrate that gradients of the film curvature induce a local magnetization that is approximately tangential to the film. The magnetization amplitude directly reflects the altermagnetic symmetry and depends on the direction of bending. It is maximal for the bending along directions of the maximal altermagnetic splitting of the magnon bands. A periodically bent film of sinusoidal shape possesses a total magnetic moment per period $\propto {\mathcal{A}}^2{q}^4$, where $\mathcal{A}$ and $q$ are the bending amplitude and wave vector, respectively. The total magnetic moment is perpendicular to the plane of the unbent film and its direction (up or down) is determined by the bending direction. A film roll-up to a nanotube possesses a toroidal moment directed along the tube $\propto {\delta }_r/r^2$ per one coil, where $r$ and ${\delta }_r$ are the coil radius and the pitch between coils. All these analytical predictions agree with numerical spin-lattice simulations.

We analyze the advantage of cell size control strategies in growing populations under mortality constraints and show that growth-dependent mortality can select for accurate size control. We determine how mortality, noise, and nongenetic heritability of cell size impact long-term population growth. We derive an analytical expression for the optimal cell size. We demonstrate that size heritability enables selection to act on the distribution of cell sizes in a population to avoid viability thresholds and adapt to size- and growth-dependent mortality landscapes.

High-rate quantum error-correcting codes mitigate the imposing scale of fault-tolerant quantum computers but require efficient generation of nonlocal, many-body entanglement. We provide a linear-optical architecture with these properties, compatible with arbitrary codes and Gottesman-Kitaev-Preskill qubits on generic lattices, and featuring a natural way to leverage physical noise bias. Simulations of hyperbolic surface codes and bivariate bicycle codes, promising families of quantum low-density parity-check codes, reveal a threshold comparable to the 2D surface code with substantially better encoding rates.

We show that physical scattering observables for compact spinning objects in general relativity can depend on additional degrees of freedom in the spin tensor beyond those described by the spin vector alone. The impulse, spin kick, and leading-order waveforms exhibit such a nontrivial dependence. A signal of this additional structure is the change in the magnitude of the spin vector under conservative Hamiltonian evolution, similar to our previous studies in electrodynamics. These additional degrees of freedom describe dynamical mass multipoles of compact objects and decouple for black holes. We also show that the conservative impulse, spin kick, and change of the additional degrees of freedom are encoded in the eikonal phase.

We study $T\overline{T}$-like deformations of $d>2$ Yang-Mills theories. The standard $T\overline{T}$ flows lead to multitrace Lagrangians, and the non-Abelian gauge structures make it challenging to find Lagrangians in a closed form. However, within the geometric approach to $T\overline{T}$, we obtain the closed-form solution to the metric flow and stress-energy tensor, and show that instanton solutions are undeformed. We also introduce new symmetrized single-trace $T\overline{T}$-like deformations, whose solutions in $d=4$ include the non-Abelian Born-Infeld Lagrangian proposed by Tseytlin in 1997.

Bound states in the continuum and exceptional points are unique singularities of non-Hermitian systems. In optical implementations, the former demonstrate strong enhancement of the electromagnetic field, while the latter exhibit high sensitivity to small perturbations. Hence, exceptional points are being actively investigated as next-generation optical sensors. However, at the nanoscale, their performance is strongly constrained by parasitic radiative losses. Here, we show that several bound states in the continuum can be merged into one exceptional point, forming a new kind of singularity. The resulting state inherits properties from both, namely, it does not radiate and shows extremely high sensitivity to perturbations, making it prospective for the realization of exceptional sensing at the nanoscale. We validate our theory with numerical simulations and demonstrate the formation of second- and third-order exceptional bound states in the continuum in stacked dielectric metasurfaces.

Self-phase modulation is ubiquitous in optical systems: It provides foundational functionality to numerous photonic technologies, such as soliton generation and ultrafast pulse compression. However, it remains challenging to directly modify the coefficient of self-phase modulation, which is typically regarded as a fixed property of optical materials and structures. In this work, we overcome this limitation and demonstrate reconfigurable self-phase modulation with an integrated photonic cavity. This is achieved by introducing the engineered backaction from the reservoir photonic resonance through the cascaded second-order nonlinear coupling. The coefficient of self-phase modulation is tuned from $-2.7$ to $+4.7$ of its intrinsic value. With negative coefficients, we observe the anomalous self-phase modulation, where photonic resonances are shifted towards higher frequencies. With the reconfigurable self-phase modulation, we further demonstrate the control of spontaneous chiral symmetry breaking in the integrated photonic ring cavity.

The spontaneous periodic oscillations of underwater bubbles are typically confined to a 1D direction or within a 2D plane, whereas realizing 3D autonomous motion of bubbles remains challenging. In this Letter, we present experimental observations of a 3D-periodic orbiting bubble, produced by directing a stationary near-infrared laser at hexane, thereby extending the spectrum of multimode motions beyond the 1D and 2D paradigms. Through numerical simulation by carefully investigating both the thermodynamic and hydrodynamic parameters of several liquids, this 3D-orbiting mode is attributed to the subtle interplay between the interfacial flow due to the thermal Marangoni effect and the bulk flow from the thermal buoyancy effect. Moreover, by developing a unified physical model to elucidate the effect of liquid properties on the motion modes, a phase diagram is constructed through a single dimensionless number ($\mathrm{\Sigma }=ReSc/Ma$), providing a theoretical guidance to tailor the periodic oscillation modes. These findings not only reveal the underlying intriguing physicochemical hydrodynamics, but also possibly shed light on the bubble-mediated technologies.

In this Letter, we report the discovery of giant room-temperature odd-parity magnetoresistance (OMR) in a bilayer graphene heterostructure interfaced with ${\mathrm{Cr}}_2{\mathrm{Ge}}_2{\mathrm{Te}}_6$ (CGT). We show that the OMR is electrostatic gate-voltage tunable, exhibiting maximum value near the graphene band edges and diminishing rapidly with increasing charge carrier density. Our theoretical analysis reveals that the OMR originates from the coupling of out-of-plane components of Berry curvature and orbital magnetic moment with the applied magnetic field, signaling intrinsic time-reversal symmetry breaking in the system. This time-reversal symmetry breaking persists at room temperature within the CGT and bilayer graphene heterostructure despite the bulk CGT exhibiting ferromagnetic transition at 65 K. Our Letter opens new avenues for probing band geometric phenomena through magnetotransport measurements, especially in quantum materials where the anomalous Hall effects are immeasurably small due to the extrinsic scattering-dependent contributions canceling Berry curvature contributions.