General synthesis of two-dimensional van der Waals heterostructure arrays.

Two-dimensional van der Waals heterostructures (vdWHs) have attracted considerable interest1-4. However, most vdWHs reported so far  are created by an arduous micromechanical exfoliation and manual restacking process5, which-although versatile for proof-of-concept demonstrations6-16 and fundamental studies17-30-is clearly not scalable for practical technologies. Here we report a general synthetic strategy for two-dimensional vdWH arrays between metallic transition-metal dichalcogenides (m-TMDs) and semiconducting TMDs (s-TMDs). By selectively patterning nucleation sites on monolayer or bilayer s-TMDs, we precisely control the nucleation and growth of diverse m-TMDs with designable periodic arrangements and tunable lateral dimensions at the predesignated spatial locations, producing a series of vdWH arrays, including VSe2/WSe2, NiTe2/WSe2, CoTe2/WSe2, NbTe2/WSe2, VS2/WSe2, VSe2/MoS2 and VSe2/WS2. Systematic scanning transmission electron microscopy studies reveal nearly ideal vdW interfaces with widely tunable moiré superlattices. With the atomically clean vdW interface, we further show that the m-TMDs function as highly reliable synthetic vdW contacts for the underlying WSe2 with excellent device performance and yield, delivering a high ON-current density of up to 900 microamperes per micrometre in bilayer WSe2 transistors. This general synthesis of diverse two-dimensional vdWH arrays provides a versatile material platform for exploring exotic physics and promises a scalable pathway to high-performance devices.

IRE1α Mediates the Hypertrophic Growth of Cardiomyocytes Through Facilitating the Formation of Initiation Complex to Promote the Translation of TOP-Motif Transcripts.

BACKGROUND: Cardiomyocyte growth is coupled with active protein synthesis, which is one of the basic biological processes in living cells. However, it is unclear whether the unfolded protein response transducers and effectors directly take part in the control of protein synthesis. The connection between critical functions of the unfolded protein response in cellular physiology and requirements of multiple processes for cell growth prompted us to investigate the role of the unfolded protein response in cell growth and underlying molecular mechanisms. METHODS: Cardiomyocyte-specific inositol-requiring enzyme 1α (IRE1α) knockout and overexpression mouse models were generated to explore its function in vivo. Neonatal rat ventricular myocytes were isolated and cultured to evaluate the role of IRE1α in cardiomyocyte growth in vitro. Mass spectrometry was conducted to identify novel interacting proteins of IRE1α. Ribosome sequencing and polysome profiling were performed to determine the molecular basis for the function of IRE1α in translational control. RESULTS: We show that IRE1α is required for cell growth in neonatal rat ventricular myocytes under prohypertrophy treatment and in HEK293 cells in response to serum stimulation. At the molecular level, IRE1α directly interacts with eIF4G and eIF3, 2 critical components of the translation initiation complex. We demonstrate that IRE1α facilitates the formation of the translation initiation complex around the endoplasmic reticulum and preferentially initiates the translation of transcripts with 5' terminal oligopyrimidine motifs. We then reveal that IRE1α plays an important role in determining the selectivity and translation of these transcripts. We next show that IRE1α stimulates the translation of epidermal growth factor receptor through an unannotated terminal oligopyrimidine motif in its 5' untranslated region. We further demonstrate a physiological role of IRE1α-governed protein translation by showing that IRE1α is essential for cardiomyocyte growth and cardiac functional maintenance under hemodynamic stress in vivo. CONCLUSIONS: These studies suggest a noncanonical, essential role of IRE1α in orchestrating protein synthesis, which may have important implications in cardiac hypertrophy in response to pressure overload and general cell growth under other physiological and pathological conditions.

PPICT: an integrated deep neural network for predicting inter-protein PTM cross-talk.

Post-translational modifications (PTMs) fine-tune various signaling pathways not only by the modification of a single residue, but also by the interplay of different modifications on residue pairs within or between proteins, defined as PTM cross-talk. As a challenging question, less attention has been given to PTM dynamics underlying cross-talk residue pairs and structural information underlying protein-protein interaction (PPI) graph, limiting the progress in this PTM functional research. Here we propose a novel integrated deep neural network PPICT (Predictor for PTM Inter-protein Cross-Talk), which predicts PTM cross-talk by combining protein sequence-structure-dynamics information and structural information for PPI graph. We find that cross-talk events preferentially occur among residues with high co-evolution and high potential in allosteric regulation. To make full use of the complex associations between protein evolutionary and biophysical features, and protein pair features, a heterogeneous feature combination net is introduced in the final prediction of PPICT. The comprehensive test results show that the proposed PPICT method significantly improves the prediction performance with an AUC value of 0.869, outperforming the existing state-of-the-art methods. Additionally, the PPICT method can capture the potential PTM cross-talks involved in the functional regulatory PTMs on modifying enzymes and their catalyzed PTM substrates. Therefore, PPICT represents an effective tool for identifying PTM cross-talk between proteins at the proteome level and highlights the hints for cross-talk between different signal pathways introduced by PTMs.

Nonlinear physics of moiré superlattices.

Nonlinear physics is one of the most important research fields in modern physics and materials science. It offers an unprecedented paradigm for exploring many fascinating physical phenomena and realizing diverse cutting-edge applications inconceivable in the framework of linear processes. Here we review the recent theoretical and experimental progress concerning the nonlinear physics of synthetic quantum moiré superlattices. We focus on the emerging nonlinear electronic, optical and optoelectronic properties of moiré superlattices, including but not limited to the nonlinear anomalous Hall effect, dynamically twistable harmonic generation, nonlinear optical chirality, ultralow-power-threshold optical solitons and spontaneous photogalvanic effect. We also present our perspectives on the future opportunities and challenges in this rapidly progressing field, and highlight the implications for advances in both fundamental physics and technological innovations.

Heterozygous Variants in KCNJ10 Cause Paroxysmal Kinesigenic Dyskinesia Via Haploinsufficiency.

OBJECTIVE: Most paroxysmal kinesigenic dyskinesia (PKD) cases are hereditary, yet approximately 60% of patients remain genetically undiagnosed. We undertook the present study to uncover the genetic basis for undiagnosed PKD patients. METHODS: Whole-exome sequencing was performed for 106 PRRT2-negative PKD probands. The functional impact of the genetic variants was investigated in HEK293T cells and Drosophila. RESULTS: Heterozygous variants in KCNJ10 were identified in 11 individuals from 8 unrelated families, which accounted for 7.5% (8/106) of the PRRT2-negative probands. Both co-segregation of the identified variants and the significantly higher frequency of rare KCNJ10 variants in PKD cases supported impacts from the detected KCNJ10 heterozygous variants on PKD pathogenesis. Moreover, a KCNJ10 mutation-carrying father from a typical EAST/SeSAME family was identified as a PKD patient. All patients manifested dystonia attacks triggered by sudden movement with a short episodic duration. Patch-clamp recordings in HEK293T cells revealed apparent reductions in K+ currents of the patient-derived variants, indicating a loss-of-function. In Drosophila, milder hyperexcitability phenotypes were observed in heterozygous Irk2 knock-in flies compared to homozygotes, supporting haploinsufficiency as the mechanism for the detected heterozygous variants. Electrophysiological recordings showed that excitatory neurons in Irk2 haploinsufficiency flies exhibited increased excitability, and glia-specific complementation with human Kir4.1 rescued the Irk2 mutant phenotypes. INTERPRETATION: Our study established haploinsufficiency resulting from heterozygous variants in KCNJ10 can be understood as a previously unrecognized genetic cause for PKD and provided evidence of glial involvement in the pathophysiology of PKD. ANN NEUROL 2024.

Superconductors, orbital magnets and correlated states in magic-angle bilayer graphene.

Superconductivity can occur under conditions approaching broken-symmetry parent states1. In bilayer graphene, the twisting of one layer with respect to the other at 'magic' twist angles of around 1 degree leads to the emergence of ultra-flat moiré superlattice minibands. Such bands are a rich and highly tunable source of strong-correlation physics2-5, notably superconductivity, which emerges close to interaction-induced insulating states6,7. Here we report the fabrication of magic-angle twisted bilayer graphene devices with highly uniform twist angles. The reduction in twist-angle disorder reveals the presence of insulating states at all integer occupancies of the fourfold spin-valley degenerate flat conduction and valence bands-that is, at moiré band filling factors ν = 0, ±1, ±2, ±3. At ν ≈ -2, superconductivity is observed below critical temperatures of up to 3 kelvin. We also observe three new superconducting domes at much lower temperatures, close to the ν = 0 and ν = ±1 insulating states. Notably, at ν = ± 1 we find states with non-zero Chern numbers. For ν = -1 the insulating state exhibits a sharp hysteretic resistance enhancement when a perpendicular magnetic field greater than 3.6 tesla is applied, which is consistent with a field-driven phase transition. Our study shows that broken-symmetry states, interaction-driven insulators, orbital magnets, states with non-zero Chern numbers and superconducting domes occur frequently across a wide range of moiré flat band fillings, including close to charge neutrality. This study provides a more detailed view of the phenomenology of magic-angle twisted bilayer graphene, adding to our evolving understanding of its emergent properties.

Interplay of Landau Quantization and Interminivalley Scatterings in a Weakly Coupled Moiré Superlattice.

Double-layer quantum systems are promising platforms for realizing novel quantum phases. Here, we report a study of quantum oscillations (QOs) in a weakly coupled double-layer system composed of a large-angle twisted-double-bilayer graphene (TDBG). We quantify the interlayer coupling strength by measuring the interlayer capacitance from the QOs pattern at low temperatures, revealing electron-hole asymmetry. At high temperatures when SdHOs are thermally smeared, we observe resistance peaks when Landau levels (LLs) from two moiré minivalleys are aligned, regardless of carrier density; eventually, it results in a 2-fold increase of oscillating frequency in D, serving as compelling evidence of the magneto-intersub-band oscillations (MISOs) in double-layer systems. The temperature dependence of MISOs suggests that electron-electron interactions play a crucial role and the scattering times obtained from MISO thermal damping are correlated with the interlayer coupling strength. Our study reveals intriguing interplays among Landau quantization, moiré band structure, and scatterings.

Tip Growth of Quasi-Metallic Bilayer Graphene Nanoribbons with Armchair Chirality.

Graphene nanoribbons (GNRs), quasi one-dimensional (1D) narrow strips of graphene, have shown promise for high-performance nanoelectronics due to their exceptionally high carrier mobility and structurally tunable bandgaps. However, producing chirality-uniform GNRs on insulating substrates remains a big challenge. Here, we report the successful growth of bilayer GNRs with predominantly armchair chirality and ultranarrow widths (<5 nm) on insulating hexagonal boron nitride (h-BN) substrates using chemical vapor deposition (CVD). The growth of GNRs is catalyzed by transition metal nanoparticles, including Fe, Co, and Ni, through a unique tip-growth mechanism. Notably, GNRs catalyzed by Ni exhibit a high purity (97.3%) of armchair chirality. Electron transport measurements indicate that the ultrathin bilayer armchair GNRs exhibit quasi-metallic behavior. This quasi-metallicity is further supported by density functional theory (DFT) calculations, which reveal a significantly reduced bandgap in bilayer armchair GNRs. The chirality-specific GNRs reported here offer promising advancements for the application of graphene in nanoelectronics.

Broadband Sound Absorption and High Damage Resistance in a Turtle Shell-Inspired Multifunctional Lattice: Neural Network-Driven Design and Optimization.

Incorporating acoustic and mechanical properties into a single multifunctional structure has attracted considerable attention in engineering. However, effectively integrating these sound absorption properties and damage resistance to achieve multifunctional structural designs remains a great challenge due to imperfect design methods. In this study, the inherent mechanical properties of turtle shells by introducing dissipative pores are leveraged to present a lattice structure that possesses both excellent sound-absorg and high damage-resistant characteristics. To achieve acoustic optimization design, a universal high-fidelity neural network correction model is proposed to address the impedance calculation challenge in complex structures. Building upon this foundation, a multi-cell combination design enables to achieve high absorption through optimization with a low thickness of 50 mm, resulting in average sound absorption coefficients reaching 0.88 and 0.93 within the frequency ranges of 300-600 Hz and 500-1000 Hz, respectively. It is also found that the optimized structures exhibit exceptional damage resistance under varying relative densities via the coupling effect of the shell thickness on the acoustic and mechanical properties. Overall, this work introduces a novel paradigm for designing intricate multifunctional structures with acoustic and mechanical properties while providing valuable inspiration for future research on multifunctional structure design.

Correlated Charge Density Wave Insulators in Chirally Twisted Triple Bilayer Graphene.

Electrons residing in a flat-band system can play a vital role in triggering spectacular phenomenology due to relatively large interactions and spontaneous breaking of different degeneracies. In this work, we demonstrate chirally twisted triple bilayer graphene, a new moiré structure formed by three pieces of helically stacked Bernal bilayer graphene, as a highly tunable flat-band system. In addition to the correlated insulators showing at integer moiré fillings, commonly attributed to interaction induced symmetry broken isospin flavors in graphene, we observe abundant insulating states at half-integer moiré fillings, suggesting a longer-range interaction and the formation of charge density wave insulators which spontaneously break the moiré translation symmetry. With weak out-of-plane magnetic field applied, as observed half-integer filling states are enhanced and more quarter-integer filling states appear, pointing toward further quadrupling moiré unit cells. The insulating states at fractional fillings combined with Hartree-Fock calculations demonstrate the observation of a new type of correlated charge density wave insulators in graphene and points to a new accessible twist manner engineering correlated moiré electronics.

ATF4 Protects the Heart From Failure by Antagonizing Oxidative Stress.

BACKGROUND: Cellular redox control is maintained by generation of reactive oxygen/nitrogen species balanced by activation of antioxidative pathways. Disruption of redox balance leads to oxidative stress, a central causative event in numerous diseases including heart failure. Redox control in the heart exposed to hemodynamic stress, however, remains to be fully elucidated. METHODS: Pressure overload was triggered by transverse aortic constriction in mice. Transcriptomic and metabolomic regulations were evaluated by RNA-sequencing and metabolomics, respectively. Stable isotope tracer labeling experiments were conducted to determine metabolic flux in vitro. Neonatal rat ventricular myocytes and H9c2 cells were used to examine molecular mechanisms. RESULTS: We show that production of cardiomyocyte NADPH, a key factor in redox regulation, is decreased in pressure overload-induced heart failure. As a consequence, the level of reduced glutathione is downregulated, a change associated with fibrosis and cardiomyopathy. We report that the pentose phosphate pathway and mitochondrial serine/glycine/folate metabolic signaling, 2 NADPH-generating pathways in the cytosol and mitochondria, respectively, are induced by transverse aortic constriction. We identify ATF4 (activating transcription factor 4) as an upstream transcription factor controlling the expression of multiple enzymes in these 2 pathways. Consistently, joint pathway analysis of transcriptomic and metabolomic data reveal that ATF4 preferably controls oxidative stress and redox-related pathways. Overexpression of ATF4 in neonatal rat ventricular myocytes increases NADPH-producing enzymes' whereas silencing of ATF4 decreases their expression. Further, stable isotope tracer experiments reveal that ATF4 overexpression augments metabolic flux within these 2 pathways. In vivo, cardiomyocyte-specific deletion of ATF4 exacerbates cardiomyopathy in the setting of transverse aortic constriction and accelerates heart failure development, attributable, at least in part, to an inability to increase the expression of NADPH-generating enzymes. CONCLUSIONS: Our findings reveal that ATF4 plays a critical role in the heart under conditions of hemodynamic stress by governing both cytosolic and mitochondrial production of NADPH.

The chromosome-scale reference genome of mirid bugs (Adelphocoris suturalis) genome provides insights into omnivory, insecticide resistance, and survival adaptation.

BACKGROUND: Adelphocoris suturalis (Hemiptera: Miridae) is a notorious agricultural pest, which causes serious economic losses to a diverse range of agricultural crops around the world. The poor understanding of its genomic characteristics has seriously hindered the establishment of sustainable and environment-friendly agricultural pest management through biotechnology and biological insecticides. RESULTS: Here, we report a chromosome-level assembled genome of A. suturalis by integrating Illumina short reads, PacBio, 10x Chromium, and Hi-C mapping technologies. The resulting 1.29 Gb assembly contains twelve chromosomal pseudomolecules with an N50 of 1.4 and 120.6 Mb for the contigs and scaffolds, respectively, and carries 20,010 protein-coding genes. The considerable size of the A. suturalis genome is predominantly attributed to a high amount of retrotransposons, especially long interspersed nuclear elements (LINEs). Transcriptomic and phylogenetic analyses suggest that A. suturalis-specific candidate effectors, and expansion and expression of gene families associated with omnivory, insecticide resistance and reproductive characteristics, such as digestion, detoxification, chemosensory receptors and long-distance migration likely contribute to its strong environmental adaptability and ability to damage crops. Additionally, 19 highly credible effector candidates were identified and transiently overexpressed in Nicotiana benthamiana for functional assays and potential targeting for insect resistance genetic engineering. CONCLUSIONS: The high-quality genome of A. suturalis provides an important genomic landscape for further investigations into the mechanisms of omnivory, insecticide resistance and survival adaptation, and for the development of integrated management strategies.

Weyl Phonons in Chiral Crystals.

Chirality is an indispensable concept that pervades fundamental science and nature, manifesting itself in diverse forms, e.g., quasiparticles, and crystal structures. Of particular interest are Weyl phonons carrying specific Chern numbers and chiral phonons doing circular motions. Up to now, they have been studied independently and the interpretations of chirality seem to be different in these two concepts, impeding our understanding. Here, we demonstrate that they are entangled in chiral crystals. Employing a typical chiral crystal of elementary tellurium (Te) as a case study, we expound on the intrinsic relationship between Chern number of Weyl phonons and pseudoangular momentum (PAM, lph) of chiral phonons. We propose Raman scattering as a new technique to demonstrate the existence of Weyl phonons in Te, by detecting the chirality-induced energy splitting between the two constituent chiral phonon branches for Weyl phonons. Moreover, we also observe the obstructed phonon surface states for the first time.

MoS2-Thin Film Transistor Based Flexible 2T1C Driving Circuits for Active-Matrix Displays.

Two-dimensional (2D) semiconductors offer great potential as high-performance materials for thin film transistors (TFTs) in displays. Their thin, stable, and flexible nature, along with excellent electrical properties, makes them suitable for flexible displays. However, previous demonstrations lacked clear superiority in pixel resolution and TFT performance. Here we present the flexible 2T1C pixel driving circuit for active-matrix displays based on high-quality large-scale monolayer MoS2. A gate-first fabrication process was developed for flexible MoS2-TFTs, showing a remarkable carrier mobility (average at 52.8 cm2 V-1 s-1), high on/off ratio (average at 1.5 × 108), and negligible hysteresis. The driving current can be modulated by pulsed input voltages and demonstrates a stable and prompt response to both frequency and amplitude. We also demonstrated a 10 × 10 active-matrix with high resolution of 508 pixels per inch, exhibiting 100% yield and high uniformity. The driving circuit works well under bending up to ∼0.91% strain, highlighting its normal functions in flexible displays.

Scaling of MoS2 Transistors and Inverters to Sub-10 nm Channel Length with High Performance.

Two-dimensional (2D) semiconductors such as monolayer molybdenum disulfide (MoS2) are promising building blocks for ultrascaled field effect transistors (FETs), benefiting from their atomic thickness, dangling-bond-free flat surface, and excellent gate controllability. However, despite great prospects, the fabrication of 2D ultrashort channel FETs with high performance and uniformity remains a challenge. Here, we report a self-encapsulated heterostructure undercut technique for the fabrication of sub-10 nm channel length MoS2 FETs. The fabricated 9 nm channel MoS2 FETs exhibit superior performances compared with sub-15 nm channel length including the competitive on-state current density of 734/433 µA/µm at VDS = 2/1 V, record-low DIBL of ∼50 mV/V, and superior on/off ratio of 3 × 107 and low subthreshold swing of ∼100 mV/dec. Furthermore, the ultrashort channel MoS2 FETs fabricated by this new technique show excellent homogeneity. Thanks to this, we scale the monolayer inverter down to sub-10 nm channel length.

The gut microbiome and serum metabolome are altered and interrelated in patients with intracranial atherosclerotic stenosis.

OBJECTIVES: To evaluate the relationship among the gut microbiome, serum metabolites and the Intracranial atherosclerosis stenosis. MATERIALS AND METHODS: Integrated analysis of 16S rDNA sequencing of fecal samples and untargeted serum metabolomics was applied to identify alterations in the gut microbiome and serum metabolome in 29 Intracranial atherosclerosis stenosis patients and 29 healthy control individuals. RESULTS: Compared to healthy control individuals, the abundances of forty-five genera and one hundred seventy-seven metabolites were significantly altered in Intracranial atherosclerosis stenosis patients. At the species level, the Intracranial atherosclerosis stenosis group exhibited higher abundances of Bacteroidetes and lower abundances of Megaphaera and Muribacoccaceae. Microbial functional prediction analysis revealed enhanced activity of bacterial chemotaxis and oxidative phosphorylation within the Intracranial atherosclerosis stenosis group. In terms of metabolomic findings, the levels of dulcitol were significantly increased in the Intracranial atherosclerosis stenosis group. The levels of specific metabolites within the phosphatidylcholine and lysophosphatidylcholine families, such as PC (14:0e/24:4) and LPC 20:5, were increased, while the levels of certain other specific metabolites were decreased. Dysregulation of certain pathways, such as unsaturated fatty acid metabolism, arginine and proline metabolism may be involved in the development of Intracranial atherosclerosis stenosis. Correlation analysis of the gut microbiome and metabolites revealed a positive correlation between Bacteroides and multiple metabolites, such as Acar 12:3 and PC (8:0/22:6). CONCLUSIONS: Our analysis revealed that Bacteroides is a key bacterial genus in gut dysbiosis and may be related to the development of Intracranial atherosclerosis stenosis.

Facile Fabrication of Zeolitic Imidazolate Framework-8@Regenerated Cellulose Nanofibrous Membranes for Effective Adsorption of Tetracycline Hydrochloride.

The excessive utilization of antimicrobials in humans and animals has resulted in considerable environmental contamination, necessitating the development of high-performance antibiotic adsorption media. A significant challenge is the development of composite nanofibrous materials that are both beneficial and easy to fabricate, with the aim of improving adsorption capacity. Herein, a new kind of zeolitic imidazolate framework-8 (ZIF-8)-modified regenerated cellulose nanofibrous membrane (ZIF-8@RC NFM) was designed and fabricated by combining electrospinning and in situ surface modification technologies. Benefiting from its favorable surface wettability, enhanced tensile strength, interconnected porous structure, and relatively large specific surface area, the resulting ZIF-8@RC NFMs exhibit a relatively high adsorption capacity for tetracycline hydrochloride (TCH) of 105 mg g-1 within 3 h. Moreover, a Langmuir isotherm model and a pseudo-second-order model have been demonstrated to be more appropriate for the description of the TCH adsorption process of ZIF-8@RC-3 NFMs. Additionally, this composite fibrous material could keep a relatively stable adsorption capability under various ionic strengths. The successful fabrication of the novel ZIF-8@RC NFMs may shed light on the further development of wastewater adsorption treatment materials.

Photoresponse of Solution-Synthesized Graphene Nanoribbon Heterojunctions on Diamond Indicating Phototunable Photodiode Polarity.

Graphene nanoribbon heterostructures and heterojunctions have attracted interest as next-generation molecular diodes with atomic precision. Their mass production via solution methods and prototypical device integration remains to be explored. Here, the bottom-up solution synthesis and characterization of liquid-phase-processable graphene nanoribbon heterostructures (GNRHs) are demonstrated. Joint photoresponsivity measurements and simulations provide evidence of the structurally defined heterostructure motif acting as a type-I heterojunction. Real-time, time-dependent density functional tight-binding simulations further reveal that the photocurrent polarity can be tuned at different excitation wavelengths. Our results introduce liquid-phase-processable, self-assembled heterojunctions for the development of nanoscale diode circuitry and adaptive hardware.

Imaging gate-tunable Tomonaga-Luttinger liquids in 1H-MoSe2 mirror twin boundaries.

One-dimensional electron systems exhibit fundamentally different properties than higher-dimensional systems. For example, electron-electron interactions in one-dimensional electron systems have been predicted to induce Tomonaga-Luttinger liquid behaviour. Naturally occurring grain boundaries in single-layer transition metal dichalcogenides exhibit one-dimensional conducting channels that have been proposed to host Tomonaga-Luttinger liquids, but charge density wave physics has also been suggested to explain their behaviour. Clear identification of the electronic ground state of this system has been hampered by an inability to electrostatically gate such boundaries and tune their charge carrier concentration. Here we present a scanning tunnelling microscopy and spectroscopy study of gate-tunable mirror twin boundaries in single-layer 1H-MoSe2 devices. Gating enables scanning tunnelling microscopy and spectroscopy for different mirror twin boundary electron densities, thus allowing precise characterization of electron-electron interaction effects. Visualization of the resulting mirror twin boundary electronic structure allows unambiguous identification of collective density wave excitations having two velocities, in quantitative agreement with the spin-charge separation predicted by finite-length Tomonaga-Luttinger liquid theory.

UItra-low friction and edge-pinning effect in large-lattice-mismatch van der Waals heterostructures.

Two-dimensional heterostructures are excellent platforms to realize twist-angle-independent ultra-low friction due to their weak interlayer van der Waals interactions and natural lattice mismatch. However, for finite-size interfaces, the effect of domain edges on the friction process remains unclear. Here we report the superlubricity phenomenon and the edge-pinning effect at MoS2/graphite and MoS2/hexagonal boron nitride van der Waals heterostructure interfaces. We found that the friction coefficients of these heterostructures are below 10-6. Molecular dynamics simulations corroborate the experiments, which highlights the contribution of edges and interface steps to friction forces. Our experiments and simulations provide more information on the sliding mechanism of finite low-dimensional structures, which is vital to understand the friction process of laminar solid lubricants.