Nature Materials最新文献

Novel two-dimensional semiconductor crystals can exhibit diverse physical properties beyond their inherent semiconducting attributes, making their pursuit paramount. Memristive properties, as exemplars of these attributes, are predominantly manifested in wide-bandgap materials. However, simultaneously harnessing semiconductor properties alongside memristive characteristics to produce memtransistors is challenging. Herein we prepared a class of semiconducting III–V-derived van der Waals crystals, specifically the H_xA_1–xBX form, exhibiting memristive characteristics. To identify candidates for the material synthesis, we conducted a systematic high-throughput screening, leading us to 44 prospective III–V candidates; of these, we successfully synthesized ten, including nitrides, phosphides, arsenides and antimonides. These materials exhibited intriguing characteristics such as electrochemical polarization and memristive phenomena while retaining their semiconductive attributes. We demonstrated the gate-tunable synaptic and logic functions within single-gate memtransistors, capitalizing on the synergistic interplay between the semiconducting and memristive properties of our two-dimensional crystals. Our approach guides the discovery of van der Waals materials with unique properties from unconventional crystal symmetries.

Superconductivity and magnetism are often antagonistic in quantum matter, although their intertwining has long been considered in frustrated-lattice systems. Here we utilize scanning tunnelling microscopy and muon spin resonance to demonstrate time-reversal symmetry-breaking superconductivity in kagome metal Cs(V, Ta)₃Sb₅, where the Cooper pairing exhibits magnetism and is modulated by it. In the magnetic channel, we observe spontaneous internal magnetism in a fully gapped superconducting state. Under the perturbation of inverse magnetic fields, we detect a time-reversal asymmetrical interference of Bogoliubov quasi-particles at a circular vector. At this vector, the pairing gap spontaneously modulates, which is distinct from pair density waves occurring at a point vector and consistent with the theoretical proposal of an unusual interference effect under time-reversal symmetry breaking. The correlation between internal magnetism, Bogoliubov quasi-particles and pairing modulation provides a chain of experimental indications for time-reversal symmetry-breaking kagome superconductivity.

Most two-dimensional (2D) materials experimentally studied so far have hexagons as their building blocks. Only a few exceptions, such as PdSe₂, are lower in energy in pentagonal phases and exhibit pentagons as building blocks. Although theory has predicted a large number of pentagonal 2D materials, many of these are metastable and their experimental realization is difficult. Here we report the successful synthesis of a metastable pentagonal 2D material, monolayer pentagonal PdTe₂, by symmetry-driven epitaxy. Scanning tunnelling microscopy and complementary spectroscopy measurements are used to characterize this material, which demonstrates well-ordered low-symmetry atomic arrangements and is stabilized by lattice matching with the underlying Pd(100) substrate. Theoretical calculations, along with angle-resolved photoemission spectroscopy, reveal monolayer pentagonal PdTe₂ to be a semiconductor with an indirect bandgap of 1.05 eV. Our work opens an avenue for the synthesis of pentagon-based 2D materials and gives opportunities to explore their applications such as multifunctional nanoelectronics.

Twist engineering has emerged as a powerful approach for modulating electronic properties in van der Waals heterostructures. While theoretical works have predicted the modulation of spin texture in graphene-based heterostructures by twist angle, experimental studies are lacking. Here, by performing spin precession experiments, we demonstrate tunability of the spin texture and associated spin-charge interconversion with twist angle in WSe₂/graphene heterostructures. For specific twist angles, we detect a spin component radial with the electron's momentum, in addition to the standard orthogonal component. Our results show that the helicity of the spin texture can be reversed by twist angle, highlighting the critical role of the twist angle in the spin-orbit properties of WSe₂/graphene heterostructures and paving the way for the development of spin-twistronic devices.

Nanoscale three-dimensional (3D) printing of metals and alloys has faced challenges in speed, miniaturization and deficiency in material properties. Traditional nanomanufacturing relies on lithographic methods with material constraints, limited resolution and slow layer-by-layer processing. This work introduces polymer-free techniques using two-photon decomposition and optical force trapping for free-space direct 3D printing of metals, metal oxides and multimetallic alloys with resolutions beyond optical limits. This method involves the two-photon decomposition of metal atoms from precursors, rapid assembly into nanoclusters via optical forces and ultrafast laser sintering, yielding dense, smooth nanostructures. Enhanced near-field optical forces from laser-induced localized surface plasmon resonance facilitate nanocluster aggregation. Our approach eliminates the need for organic materials, layer-by-layer printing and complex post-processing. Printed Mo nanowires show an excellent mechanical performance, closely resembling the behaviour of single crystals, while Mo–Co–W alloy nanowires outperform Mo nanowires. This innovation promises the customizable 3D nanoprinting of high-quality metals and metal oxides, impacting nanoelectronics, nanorobotics and advanced chip manufacturing.

Perovskite crystals—with their exceptional nonlinear optical properties, lasing and waveguiding capabilities—offer a promising platform for integrated photonic circuitry within the strong-coupling regime at room temperature. Here we demonstrate a versatile template-assisted method to efficiently fabricate large-scale waveguiding perovskite crystals of arbitrarily predefined geometry such as microwires, couplers and splitters. We non-resonantly stimulate a condensate of waveguided exciton–polaritons resulting in bright polariton lasing from the transverse interfaces and corners of our perovskite microstructures. Large blueshifts with excitation power and high mutual coherence between the different edge and corner lasing signals are detected in the far-field photoluminescence, implying that a spatially extended condensates of coherent polaritons has formed. The condensate polaritons are found to propagate over long distances in the wires from the excitation spot and can couple to neighbouring wires through large air gaps, making our platform promising for integrated polaritonic circuitry and on-chip optical devices with strong nonlinearities.

Jamming of cell collectives and associated rigidity transitions have been shown to play a key role in tissue dynamics, structure and morphogenesis. Cellular jamming is controlled by cellular density and the mechanics of cell–cell contacts. However, the contribution of subcellular organelles to the physical state of the emergent tissue is unclear. Here we report a nuclear jamming transition in zebrafish retina and brain tissues, where physical interactions between highly packed nuclei restrict cellular movements and control tissue mechanics and architecture. Computational modelling suggests that the nuclear volume fraction and anisotropy of cells control the emerging tissue physical state. Analysis of tissue architecture, mechanics and nuclear movements during eye development show that retina tissues undergo a nuclear jamming transition as they form, with increasing nuclear packing leading to more ordered cellular arrangements, reminiscent of the crystalline cellular packings in the functional adult eye. Our results reveal an important role of the cell nucleus in tissue mechanics and architecture.

Hexagonal boron nitride (hBN) has emerged as a promising protection layer for dielectric integration in the next-generation large-scale integrated electronics. Although numerous efforts have been devoted to growing single-crystal hBN film, wafer-scale ultraflat hBN has still not been achieved. Here, we report the epitaxial growth of 4 in. ultraflat single-crystal hBN on Cu_0.8Ni_0.2(111)/sapphire wafers. The strong coupling between hBN and Cu_0.8Ni_0.2(111) suppresses the formation of wrinkles and ensures the seamless stitching of parallelly aligned hBN domains, resulting in an ultraflat single-crystal hBN film on a wafer scale. Using the ultraflat hBN as a protective layer, we integrate the wafer-scale ultrathin high-κ dielectrics onto two-dimensional (2D) materials with a damage-free interface. The obtained hBN/HfO₂ composite dielectric exhibits an ultralow current leakage (2.36 × 10⁻⁶ A cm⁻²) and an ultrathin equivalent oxide thickness of 0.52 nm, which meets the targets of the International Roadmap for Devices and Systems. Our findings pave the way to the synthesis of ultraflat 2D materials and integration of future 2D electronics.