ABSTRACTWhile correlated phenomena of flat bands have been extensively studied in twisted systems, the ordered states that emerge from interactions in the intrinsic flat bands of kagome lattice materials remain largely unexplored. The newly discovered kagome metal CsCr3Sb5 offers a unique and rich platform for this research, as its multi-orbital flat bands at the Fermi surface result in a complex interplay of pressurized superconductivity, antiferromagnetism, a structural phase transition and density wave orders. Here, using ultrafast optical techniques, we provide strong spectroscopic evidence for a charge density wave transition in CsCr3Sb5, resolving previous ambiguities. Crucially, we identify rotational symmetry breaking that manifests as a three-state Potts-type nematicity. Our elastoresistance measurements directly demonstrate the electronic origin of this order, as the rotational-symmetry-breaking E2g component of the elastoresistance shows divergent behaviour around the transition temperature. This exotic nematicity results from the lifting of degeneracy of the multi-orbital flat bands, akin to phenomena seen in certain iron-based superconductors. Our study pioneers the investigation of ultrafast dynamics in flat-band systems at the Fermi surface, offering new insights into the interactions between multiple elementary excitations in strongly correlated systems.

ABSTRACTTwisted bilayer MoTe2 (tMoTe2) has recently emerged as an exceptional platform for realizing strongly correlated and topological quantum phases. Yet, its microscopic electronic structure remains largely unexplored. Here, we use scanning tunneling microscopy/spectroscopy (STM/STS) to directly image the moiré flat bands in dual-gated tMoTe2 devices with twist angles of 2.3°–3.8°. A dual-gate design allows independent tuning of band filling and displacement field, enabling detailed spectroscopic mapping. We find that the low-energy flat bands are localized at MX and XM sites and form a topological honeycomb lattice at zero electric field. An applied electric field lifts the degeneracy of the layer, driving a transition to two decoupled triangular lattices with trivial topology. Our results match first-principles calculations, revealing K-valley hybridization as the microscopic origin. At large moiré potential, we observe Wigner molecular crystals forming a Kagome lattice at filling νMX = 3, demonstrating electric-field control of topology and correlation in tMoTe2.

Exploring wave-matter interactions at extreme electromagnetic (EM) scales has long been a focal topic in multidisciplinary research, but deep-subwavelength field localization remains a persistent challenge. Here, we demonstrate an on-chip microwave oscillator with an electrical size of λ 0/865 (λ 0 is the operating wavelength) and a mode volume of 2.97×10-11λ 0 3 using the 0.18μm complementary metal-oxide-semiconductor (CMOS) process. The physical insight is based on a spoof plasmonic skyrmion resonator realized by square spiral metal lines, which simultaneously functions as a frequency selector and an energy storage element for EM signal generation. A strongly-coupled excitation structure is proposed to efficiently concentrate EM energy into the deep-subwavelength resonance structure, and a complementary cross-coupled pair is employed to compensate for the high material loss resulting from the extreme energy concentration. This work paves the way for integrating the skyrmion resonances into the CMOS chips in extremely deep-subwavelength scale, and holds great promise for miniaturized integrated circuits and systems.

ABSTRACTPolysulfides shuttle and Li2S passivation are considered key problems of lithium–sulfur (Li–S) batteries, seriously hindering sulfur recycling for practical applications. However, the prevailing strategies for introducing electrocatalysts focus mainly on the polysulfides-shuttle effect, whereas Li2S passivation involving solid conversions with high energy barriers has been rarely studied and remains challenging. Herein, we propose that applying a magnetic field (MF) to weak ferromagnetism α-Fe2O3 shows an enhanced effect, not only suppressing the polysulfides shuttle, but also alleviating Li2S passivation by synchronously catalysing polysulfides conversion and Li2S deposition/dissociation. Experimental and theoretical studies reveal that the MF can promote the consistent alignment of magnetic-domain orientations in α-Fe2O3 and enhance the electron spin polarization of the Fe 3d orbital, which shifts the center of the Fe d-band towards the Fermi level and increases the hybridization degree between Fe 3d and S 3p orbitals in α-Fe2O3–Li2S6 or α-Fe2O3–Li2S, thus enhancing the adsorption and catalysis of polysulfides and solid products. As a result, after using a 400-mT MF, the α-Fe2O3/S cathode shows outstanding cycling stability and excellent rate capability. The research demonstrates that MF-guided electrocatalysis represents an effective solution to the challenging problems of Li–S batteries.

ABSTRACTAll-solid-state lithium–sulfur batteries (ASSLSBs) show promise in balancing high energy density and safety, but face the bottleneck of sluggish sulfur conversion kinetics. Single-atom catalysts (SACs) could alleviate this by maximizing active-site utilization and intimate contact with sulfur. However, the metal centers often undergo irreversible electronic reconstruction, causing fast degradation and capacity fading. Here, we report an atomic-scale electron buffering strategy with electronegativity-matched dual-metal atom sites, which strengthen interfacial bonding with sulfur species while maintaining stability. The dual-metal Cu and Ni atoms are anchored on the polymeric carbon nitride (Cu1Ni1–PCN) to form spatial proximity (∼3.4 Å) single-atom pairs with similar electronegativity. This pair mediates electron buffering between the metals, enabling dynamic valence modulation that suppresses deactivation and enhances interfacial d–p orbital hybridization with sulfur. Consequently, the catalyst enables consistently low activation energy during long cycling, retaining a high capacity of 948 mAh g−1 after 2500 cycles at 1 mA cm−2 and exhibiting almost no capacity decay over 7000 cycles at 2 mA cm−2. This work establishes electron buffering as a robust approach to stabilize atomic-scale catalysts and offers a general design framework for high-performance sulfur electrocatalysis in ASSLSBs.

Transformation optics (TO) enables unprecedented electromagnetic wave manipulation through the theory of coordinate transformations, yet its practical implementation has been fundamentally constrained by narrowband operation stemming from extreme material requirements. To break this spectral bottleneck, a dual-mode metamaterial architecture synergizing Brewster-angle broadband transmission with Fabry-Pérot multiband resonance is proposed. This approach leverages cascaded impedance-engineered slot cavities-constructed from conventional dielectrics and standard metallic patterning-to achieve transformation invariance while eliminating exotic material needs. This framework enables two spectral functionalities simultaneously in a single platform: (i) omnidirectional multiband operation through discrete resonances and (ii) broadband unidirectional performance via angular-selective Brewster transmission. Experimental validation demonstrates a full-parameter invisibility cloak maintaining >88.4% transmittance across X-band frequencies (7.5-12.5 GHz) with ±70[Formula: see text] angular tolerance, alongside a retroreflector achieving near-unity efficiency in X/K bands (12-24 GHz) within ±60[Formula: see text] illumination. By resolving the fundamental conflict between bandwidth and geometric complexity in TO designs, this work establishes a scalable paradigm for multifunctional wave-control devices spanning radar stealth to next-generation communications.

Persistent 4%-22% gaps in nitrogen (N) mass balances have hindered sustainable N management in paddy agriculture. Periphyton are known N sinks, yet their role in paddies remains unclear. We used 15N tracing in 840 paddies across China to quantify periphyton-associated N pools and their fate. Periphyton captured 6%-24% (mean: 12%) of the applied N fertilizer (i.e. ∼0.8 Tg N yr-1 nationwide), effectively accounting for the missing N in previous budgets. Most of the sequestered N was stored as bioavailable ammonium. Partitioning analysis revealed that periphyton-mediated N was subsequently released into residual soil N (512-640 kt), denitrification (56-128 kt) and ammonia volatilization (64-232 kt). Thus, periphyton act as transient N reservoirs, immobilizing N fertilizer early in the growing season and gradually releasing it through biomass decay. This overlooked pathway closes a critical gap in agroecosystem N cycling and supports more precise N management in rice systems.

Elemental mercury (Hg0) is a pervasive pollutant of global concern. Recent research shows that global Hg0 emissions are significantly underestimated, but the additional sources contributing to this gap are unclear. Here, we demonstrate that chemolithoautotrophic microorganisms, such as sulfur-oxidizing and iron-oxidizing bacteria that are ubiquitous in diverse environments, utilize mercury sulfide (HgS) nanoparticles to support growth while releasing substantial amounts of Hg0. Unlike dissolved Hg(II) species, HgS nanoparticles (HgSNP) are internalized into bacterial cells through an adenosine triphosphate (ATP)-independent, highly energy-efficient process. This enhanced internalization leads to rapid metabolism of HgSNP via sulfur-oxidation, as well as the subsequent reduction of the released Hg(II) to Hg0 mediated by the mer operon, superoxide or cytochrome c. Our modeling results show that the annual emission flux of Hg0 from this previously unrecognized source can reach 272.44±134.99 tonnes, equivalent to that of geogenic Hg0 emissions and matching that of the fourth largest anthropogenic source, cement production.

ABSTRACTThe transfer-free synthesis of inch-scale high-quality graphene on insulators is of paramount importance for emerging electronic and optoelectronic applications. Nevertheless, recent efforts at direct growth via the chemical-vapor-deposition route failed to produce monolayer graphene with a large wafer size (i.e. 6 inches) affording scalable uniformity and batch repeatability. Here, we report a co-field-reconciled synthetic strategy in which the synergistic optimization of thermal and gas-flow fields readily allows the uniform growth of 6-inch monolayer graphene over a sapphire wafer with batch-production capability. The temperature and flow fields are dictated via the concurrent deployment of a graphite gasket and a gas distributor plate, with the effectiveness evidenced by simulation and wafer-level characterization results. Theoretical calculations reveal that our route lowers the methane-decomposition barrier and restrains multilayer nucleation. The thus-prepared graphene exhibits impressive crystal quality, spatial uniformity and electrical performance. Six-inch wafer-scale top-gated graphene field-effect transistor arrays showcase the consistent device characteristics, with a room-temperature mobility average rivaling the state-of-the-art examples. The generality of such a route could be extended to other insulating substrates, including SiC, WC, Si3N4 and SiO2. This work achieves co-field optimization during wafer-level graphene growth over insulators and lays the foundation for advancing the large-scale integration of graphene.

ABSTRACTThe success of data-driven deep learning in computational imaging is often constrained by the need for extensive labeled datasets. Recent progress in physics-informed neural networks has mitigated this issue by integrating analytical physical models, allowing data-free training. However, for challenging imaging tasks, such as to simultaneously acquire complex amplitude light-field information, the weak physical constraints of conventional imaging hardware largely limit the spatiotemporal imaging resolution. Here, we propose an extremely simple yet powerful monocular camera for complex amplitude imaging based on a liquid-crystal (LC)-lens-informed Fourier neural network. Combining a polarization-multiplexed bifocal LC lens with a polarization image sensor, the camera acts as a polarization phase-shifting radial shearing interferometer. Without any labeled data, the LC-lens-informed Fourier neural network can reconstruct the complex amplitude of a variety of scenes from captured polarization images in a single shot with high fidelity. We experimentally demonstrate the reconstruction of wavefront aberrations involving 136 Zernike modes with a phase accuracy of λ/35 as well as static hologram retrieval and dynamic monitoring of air flow and flame fields. This complementary hardware-algorithm framework offers a promising pathway for developing compact, versatile and high-performance complex amplitude imaging systems for adaptive optics, hologram reconstruction and material diagnosis applications.