Implantable silicon neural probes with nanophotonic phased arrays for single-lobe beam steering.

In brain activity mapping with optogenetics, patterned illumination is crucial for targeted neural stimulation. However, due to optical scattering in brain tissue, light-emitting implants are needed to bring patterned illumination to deep brain regions. A promising solution is silicon neural probes with integrated nanophotonic circuits that form tailored beam patterns without lenses.

Two-Dimensional Organic-Inorganic van der Waals Hybrids.

Two-dimensional organic-inorganic (2DOI) van der Waals hybrids (vdWhs) have emerged as a groundbreaking subclass of layer-stacked (opto-)electronic materials. The development of 2DOI-vdWhs via systematically integrating inorganic 2D layers with organic 2D crystals at the molecular/atomic scale extends the capabilities of traditional 2D inorganic vdWhs, thanks to their high synthetic flexibility and structural tunability. Constructing an organic-inorganic hybrid interface with atomic precision will unlock new opportunities for generating unique interfacial (opto-)electronic transport properties by combining the strengths of organic and inorganic layers, thus allowing us to satisfy the growing demand for multifunctional applications.

Controllable orbital angular momentum monopoles in chiral topological semimetals.

The emerging field of orbitronics aims to generate and control orbital angular momentum for information processing. Chiral crystals are promising orbitronic materials because they have been predicted to host monopole-like orbital textures, where the orbital angular momentum aligns isotropically with the electron's crystal momentum. However, such monopoles have not yet been directly observed in chiral crystals.

3D-printed microstructured alginate scaffolds for neural tissue engineering.

Alginate (Alg) is a versatile biopolymer for scaffold engineering and a bioink component widely used for direct cell printing. However, due to a lack of intrinsic cell-binding sites, Alg must be functionalized for cellular adhesion when used as a scaffold. Moreover, direct cell-laden ink 3D printing requires tedious disinfection procedures and cell viability is compromised by shear stress.

Optimization of a programmable /2-pitch optical phased array.

A challenge in optical phased arrays (OPAs) is to achieve single-lobe emission using densely spaced emitters without incurring inter-waveguide optical crosstalk. Here, we propose to heuristically optimize the amplitude and phase of each grating antenna in an OPA to correct for optical non-idealities, including fabrication variations and inter-waveguide crosstalk. This method was applied to a silicon photonic integrated circuit with 1 mm-long gratings at 775 nm spacing for operation in a wavelength range of 1450-1650 nm.

Giant Topological Hall Effect and Colossal Magnetoresistance in Heusler Ferromagnet near Room Temperature.

Colossal magnetoresistance (CMR) is an exotic phenomenon that allows for the efficient magnetic control of electrical resistivity and has attracted significant attention in condensed matter due to its potential for memory and spintronic applications. Heusler alloys are the subject of considerable interest in this context due to the electronic properties that result from the nontrivial band topology. Here, the observation of CMR near room temperature is reported in the shape memory Heusler alloy NiMnIn, which is attributed to the combined effects of magnetic field-induced martensite twin variant reorientation (MFIR) and magnetic field-induced structural phase transformation (MFIPT).

Reducing crystal symmetry to generate out-of-plane Dzyaloshinskii-Moriya interaction.

The Dzyaloshinskii-Moriya antisymmetric exchange interaction (DMI) stabilises topological spin textures with promising future spintronics applications. According to crystal symmetry, the DMI can be categorized as four different types that favour different chiral textures. Unlike the other three extensively-investigated types, out-of-plane DMI, as the last type that favours in-plane chirality, remained missing so far.

Metal-Phthalocyanine-Based Two-Dimensional Conjugated Metal-Organic Frameworks for Electrochemical Glycerol Oxidation Reaction.

Electrochemical glycerol oxidation reaction (GOR) is a promising candidate to couple with cathodic reaction, like hydrogen evolution reaction, to produce high-value product with less energy consumption. Two dimensional conjugated metal-organic frameworks (2D c-MOFs), comprising square-planar metal-coordination motifs (e.g.

Exciton-Exciton Interaction in Monolayer MoSe from Mutual Screening of Coulomb Binding.

Excitons in two-dimensional (2D) semiconductors are particularly exciting, as reduced screening and dimensional confinement foster their pronounced many-body interactions. Optical pumping is typically used to create excitons so as to study their properties, but at the same time such pumping can also create unbound charge carriers. This makes experimental determination of the exciton-exciton interactions difficult.

Thermal Conductivity in Biphasic Silicon Nanowires.

The work unravels the previously unexplored atomic-scale mechanism involving the interaction of phonons with crystal homointerfaces. Silicon nanowires with engineered isotopic content and crystal phases were chosen for this investigation. Crystal polytypism, manifested by the presence of both diamond cubic and rhombohedral phases within the same nanowire, provided a testbed to study the impact of phase homointerfaces on phonon transport.

Three-Dimensional Covalent Organic Framework with Dense Lithiophilic Sites as Protective Layer to Enable High-Performance Lithium Metal Battery.

Lithium (Li) metal batteries with remarkable energy densities are restrained by short lifetime and low Coulombic efficiency (CE), resulting from the accumulative Li dendrites and dead Li during cycling. Here, we prepared a new three-dimensional (3D) covalent organic framework (COF) with dense lithiophilic sites (heteoatom weight contents of 32.32 wt %) as an anodic protective layer of Li metal batteries.

Vacancies Engineering in Molybdenum Boride MBene Nanosheets to Activate Room-Temperature Ferromagnetism.

The rapid development of low energy dissipation spintronic devices has stimulated the search for air-stable 2D nanomaterials possessing room-temperature ferromagnetism. Here the experimental realization of 2D MoB nanosheets is reported with intrinsic room-temperature ferromagnetic characteristics by vacancy engineering. These nanosheets are synthesized by etching the bulk MAB phase (MoY)AlB into MoB nanosheets in ZnCl molten salt.

Long-range phase coherence and tunable second order -Josephson effect in a Dirac semimetal 1T-PtTe.

Superconducting diode effects have recently attracted much attention for their potential applications in superconducting logic circuits. Several pathways have been proposed to give rise to non-reciprocal critical currents in various superconductors and Josephson junctions. In this work, we establish the presence of a large Josephson diode effect in a type-II Dirac semimetal 1T-PtTe facilitated by its helical spin-momentum locking and distinguish it from extrinsic geometric effects.

Parallel Logic Operations in Electrically Tunable Two-Dimensional Homojunctions.

Two-dimensional materials show great potential for future electronics beyond silicon materials. Here, we report an exotic multiple-port device based on multiple electrically tunable planar p-n homojunctions formed in a two-dimensional (2D) ambipolar semiconductor, tungsten diselenide (WSe). In this device, we prepare multiple gates consisting of a global gate and several local gates, by which electrostatically induced holes and electrons are simultaneously accumulated in a WSe channel, and furthermore, at the boundaries, p-n junctions are formed as directly visualized by Kelvin probe force microscopy.

Universal and scalable synthesis of photochromic single-atom catalysts for plastic recycling.

Metal oxide nanostructures with single-atomic heteroatom incorporation are of interest for many applications. However, a universal and scalable synthesis approach with high heteroatom concentrations represents a formidable challenge, primarily due to the pronounced structural disparities between M-O and M-O units. Here, focusing on TiO as the exemplified substrate, we present a diethylene glycol-assisted synthetic platform tailored for the controlled preparation of a library of M-TiO nanostructures, encompassing 15 distinct unary M-TiO nanostructures, along with two types of binary and ternary composites.

Tunable topological phases in nanographene-based spin-1/2 alternating-exchange Heisenberg chains.

Unlocking the potential of topological order in many-body spin systems has been a key goal in quantum materials research. Despite extensive efforts, the quest for a versatile platform enabling site-selective spin manipulation, essential for tuning and probing diverse topological phases, has persisted. Here we utilize on-surface synthesis to construct spin-1/2 alternating-exchange Heisenberg chains by covalently linking Clar's goblets-nanographenes each hosting two antiferromagnetically coupled spins.

Manipulative Single Electric Dipole with Spontaneous Translational Symmetry Breaking in a Two-Dimensional Crystal.

It is widely acknowledged that quantum entities with minimal mass cannot undergo spontaneous symmetry breaking due to strong quantum fluctuations. Here, we report the discovery of a positionally settled single electric dipole that can be manipulated and electrically polarized in a monolayer CoCl-graphite heterostructure, which demonstrates an unprecedented example of spontaneous lattice-translational-symmetry breaking. Scanning tunneling microscopy and atomic force microscopy show that the solitons are intrinsic paraelectric dipoles driven by synchronous charge-lattice distortion around individual CoCl octahedrons.

Regulating Co-O covalency to manipulate mechanistic transformation for enhancing activity/durability in acidic water oxidation.

Developing earth-abundant electrocatalysts with high activity and durability for acidic oxygen evolution reaction is essential for H production, yet it remains greatly challenging. Here, guided by theoretical calculations, the challenge of overcoming the balance between catalytic activity and dynamic durability for acidic OER in CoO was effectively addressed the preferential substitution of Ru for the Co (T) site of CoO. characterization and DFT calculations show that the enhanced Co-O covalency after the introduction of Ru SAs facilitates the generation of OH* species and mitigates the unstable structure transformation direct O-O coupling.

Deep-Saddle-Shaped Nanographene Induced by Four Heptagons: Efficient Synthesis and Properties.

The construction of multiple heptagonal rings in nanographene is the key step for obtaining exotic carbon nanostructures with a negative curvature and intriguing properties. Herein, a novel saddle-shaped nanographene () with four embedded heptagons is synthesized via a highly efficient one-shot Scholl reaction from a predesigned oligophenylene precursor. Notably, a quadruple [6]helicene intermediate was also obtained and isolated by controlling the Scholl reaction conditions.

Magnetic Excitations in Ferromagnetically Coupled Spin-1 Nanographenes.

In the pursuit of high-spin building blocks for the formation of covalently bonded 1D or 2D materials with controlled magnetic interactions, -electron magnetism offers an ideal framework to engineer ferromagnetic interactions between nanographenes. As a first step in this direction, we explore the spin properties of ferromagnetically coupled triangulenes-triangular nanographenes with spin . By combining in-solution synthesis of rationally designed molecular precursors with on-surface synthesis, we successfully achieve covalently bonded triangulene dimers and trimers on Au(111).

Coexistence of Redox-Active Metal and Ligand Sites in Copper-Based Two-Dimensional Conjugated Metal-Organic Frameworks as Active Materials for Battery-Supercapacitor Hybrid Systems.

Two-dimensional (2D) conjugated metal-organic frameworks (c-MOFs) are promising materials for supercapacitor (SC) electrodes due to their high electrochemically accessible surface area coupled with superior electrical conductivity compared to traditional MOFs. In this work, porous and non-porous HHB-Cu (HHB=hexahydroxybenzene), derived through surfactant-assisted synthesis are studied as representative 2D c-MOF models with different characteristics, showing diverse reversible redox reactions with Na and Li in aqueous (10 M NaNO) and organic (1.0 M LiPF in ethylene carbonate and dimethyl carbonate) electrolytes, respectively.