The quasi-one-dimensional (quasi-1D) materials serve as an excellent platform to realize ultra-low lattice thermal conductivity for thermoelectric applications, attributed to their reduced dimensionality and weak interchain van der Waals (vdW) interactions. Herein, utilizing first-principles calculations and Boltzmann transport theory, we explore the thermoelectric transport properties of the quasi-1D Bi4RuI2. Our calculation results indicate that Bi4RuI2 exhibits extraordinarily low intrinsic interchain and intrachain lattice thermal conductivity of 0.349 and 1.851 (0.131 and 0.714) W/mK at 300 (800) K, respectively. The damped thermal transport properties originate from the low phonon group velocity and large lattice anharmonicity due to the heavy component elements, complex crystal structure, avoided-crossing effects, lone-pair electrons, and bonding hierarchy. Notably, the lattice thermal conductivity exhibits pronounced anisotropy, which is obviously smaller along the interchain direction than that along the intrachain direction due to the weaker vdW interactions between the 1D covalent chains. Furthermore, Bi4RuI2 achieves high figure-of-merit (ZT) values due to the high power-factor and low lattice thermal conductivity, which reaches maximum values of about 1.59 and 2.54 at 800 K along the interchain and intrachain directions by n-type carrier doping. These findings establish quasi-1D Bi4RuI2 as a promising candidate for high-performance low-dimensional thermoelectric materials.

Abstract The coexistence of spin density wave (SDW) and charge density wave (CDW) orders in La 3 Ni 2 O 7 has been experimentally established, yet the microscopic mechanism governing their intertwined nature remains elusive. Here, we investigate the electronic and magnetic properties of bilayer nickelates using an extended two-orbital Hubbard model that explicitly incorporates intersite Coulomb interactions. We propose a Double Spin-Charge Stripe (DSCS) configuration as a unified theoretical framework that continuously interpolates between the double spin stripe (DSS) and spin-charge stripe (SCS) phases. Our mean-field calculations reveal that the intersite Coulomb interaction V constitutes the primary driving force for CDW formation: the DSCS phase that hosting both magnetic and charge orders emerges as the thermodynamically stable ground state in La 3 Ni 2 O 7 exclusively when V exceeds a critical threshold (∼0.6 eV), thereby resolving the competition with conventional magnetic configurations. Furthermore, Hund’s coupling J H progressively enlarges the energetic separation between the DSCS phase and competing orders, consolidating the stability of the intertwined state. By analyzing the evolution of local electronic density and spin moments, we elucidate how the system traverses from the uniform DSS state to the charge-modulated SCS state as a function of electronic concentration. These findings furnish a microscopic theoretical foundation for the experimentally observed SDW-CDW coexistence and underscore the pivotal role of non-local Coulomb interactions in governing the ground-state properties of strongly correlated electron systems.

Point defects in altermagnets can create phases absent in the pristine host by selectively breaking crystal symmetries. Combining symmetry analysis, first-principles calculations, and Hamiltonian modeling, we identify how point impurities modify the altermagnetic phase. Using the pristine d- wave altermagnetic monolayer V2Se2O as a testbed, we identify three distinct classes of impurities: those that preserve spin-momentum locking, those that induce a hybrid-parity state associated with Edelstein spin conversion, and those that produce a metallic ferrimagnetic state with an anomalous Hall effect. We further discuss the robustness of two-dimensional altermagnets against point impurities. Results for other two-dimensional systems, such as Mn4N2 and 2H-FeBr3, reveal the same symmetry-based control across distinct lattices and parent spin harmonics, establishing defect geometry as a general route for engineering spin textures and transport properties.

Host-guest crystalline materials with strong anharmonicity exhibiting long-range order and local disorder offer a paradigm for ideal thermoelectric model known as the "phonon-glass electron-crystal" (PGEC), which ensures efficient electrical conduction characteristic of crystals while suppressing thermal transport in a glasslike manner. It is widely accepted that guest atoms introduce low-frequency low-lying optical phonons (referred to as rattling modes), which intensely scatter the acoustic phonons, thereby drastically reducing lattice thermal conductivity (kappa L). In quasi-one-dimensional (Q-1D) thermoelectrics, this mechanism is conceptualized as covalent 1D chains forming the host framework, with isolated interchain ions acting as charge-balancing rattlers to further dampen kappa L. However, our first-principles studies of the Q-1D perovskite 8-CsSnI3 reveal that the covalent 1D chains serving as host frames also produce low-lying optical phonons, which introduce additional three-phonon scattering channels. Utilizing self-consistent phonon theory and Wigner transport formalism, we capture phonon frequency renormalization and wavelike coherent scattering. This approach uncovers an ultralow kappa L with weak temperature dependence, consistent with the results from homogeneous nonequilibrium molecular dynamics. Furthermore, based on a low-order expansion of electron-phonon coupling, we estimate a thermoelectric figure of merit ZT up to 0.53 (0.92) at 300 (425) K for 8-CsSnI3. Notably, we identify the low-lying optical branches originating from the antiparallel sliding of the host 1D chains, offering additional phonon scattering channels for damping phonon transport. These findings offer new microscopic insights into Q-1D thermoelectric transport and provide a viable material platform and a design scheme to explore PGEC behavior in anisotropic systems.

Characterizing structural disorder in solids is of significant challenge, which requires new strategy on probing and describing local structures over different scales and uncovering coherent ordering hidden in the structural disorder. Herein, we demonstrate a multimodal solution for structural disorder in Na2(1- x )Mg1- xSi1+ xO4 sodium-ion electrolytes with a stuffed cristobalite tetrahedral network. Neutron pair distribution function analysis combined with reverse Monte Carlo simulations was employed to probe the structural disorder in nanometer-scale supercells, uncovering the hidden correlated Mg/Si disorder or local Mg/Si order forming neighboring pure Mg (or Mg-rich) and Si columns. This correlated disorder was further validated by solid state 29Si nuclear magnetic resonance (NMR) spectroscopy and NMR-guided structure screenings. The sodium cations in the tunnels were proposed to be interstitial-like mobile charge carriers for ionic conduction in Na2(1- x )Mg1- xSi1+ xO4 referring to the parent cristobalite structure. Both sodium contents within the tunnels and structural disorder level play competing roles in the sodium migration, while local Mg/Si order may minimize distortion of tetrahedral network and therefore maximize the tunnel bottlenecks promoting sodium migration. This work provides practicable multimodal solution strategy to solve the commonly complex structural disorders and unveil inherently local order with wide applicability in functional materials, enhancing understanding of structure-property relationship.

Ternary layered nitrides have garnered widespread attention due to their unique electrical, optical and optoelectronic properties, which are promising for the fabrication of low-cost and highefficiency optoelectronic materials, solar cell materials and photocatalysts. Although there are no experimental reports on BaTiN2 to date, BaZrN2 and BaHfN2 have been synthesized experimentally by solid state method. However, their optical and electrical transport properties have not been systematically investigated. The purpose of this paper is to systematically investigates the mechanical, electronic, optical absorption, carrier transport, and dielectric response properties of BaMN2 (M = Ti, Zr, Hf) nitrides by first-principles calculations based on density functional theory. Due to the quasi-two-dimensional layered arrangement of [MN2]2- slabs, the ionic bonds between Ba2+ and N3-, and the weak interactions between the slabs, deformation along this direction is most likely to occur under the action of external stress. BaMN2 nitrides exhibit significant anisotropic physical properties. Firstly, the mechanical properties of BaMN2, such as bulk modulus, shear modulus, Young's modulus and Poisson's ratio, show prominent anisotropy. The lower modulus, higher Poisson's ratios and Pugh's modulus ratios indicate good flexibility of the BaMN2 nitrides. In addition, BaMN2 has indirect bandgap values (1.75-2.25 eV) within the visible-light energy range, which meets the basic requirement for the band gap of a photocatalyst for water splitting (greater than 1.23 eV). Moreover, BaMN2 has suitable band-edge positions. The appropriate bandgap values and band-edge positions indicate their broad application prospects in the absorber layer of solar cells and photocatalytic water decomposition. Attributed to the pronounced differences in the effective mass of its charge carriers in different directions, BaMN2 exhibit ultrahigh anisotropic carrier mobilities (on the order of 103 cm2s-1v-1) and lower exciton binding energies. At the same time, there are significant differences in atomic arrangement and bonding interactions along the in-plane and out of plane directions, resulting in high anisotropic visible-light absorption coefficients (on the order of 105 cm-1) in the low energy regions. In contrast, the opportunities for electrons to transition from occupied to unoccupied states increase, leading to more complex light absorption and relatively reduced anisotropy in higher energy regions. Furthermore, the special layered structure has lower polarizability and higher vibration frequency along the vertical direction perpendicular to the [MN2]2- layers, rendering BaMN2 nitrides show high dielectric constants. These excellent anisotropic mechanical, optoelectronic, and transport properties allow BaMN2 layered nitrides to be used as promising semiconductor materials in the fields of optoelectronics, photovoltaics, and photocatalysis.

Pressure applications can enable the tuning of atomic/defect ordering and provide access to new functional materials. Here, we report that pressure-induced structural transformation featuring disorder-order transition of both cations and vacancies in the 8-layer deficient hexagonal perovskite tantalate dielectrics Ba8ZnTa6O24, which transformed the structure from twin to shift and remarkably lowered the temperature coefficient of resonant frequency τf down to near zero (∼0.56 ppm/°C) from 38 ppm/°C for the twinned precursor. The atomic scale STEM-HAADF and EDS results confirm the ordering of Zn in the Ta host at the nanometer scale in the shifted material featuring well-ordered Ba8ZnTa6O24 slabs intergrown with Ba3ZnTa2O9 and Ba5Ta4O15 monolayers and anti-phase grain boundaries as planar defects. The pressure-induced twin-shift structural transformation of Ba8ZnTa6O24 features the rare constant concentration of the hexagonal stacked layers, which is allowed by the vacancy ordering at the central layers of face-shared octahedral (FSO) trimers avoiding the FSO B-B repulsion, and remarkably the faster cationic ordering kinetics compared with the 2:1 ordered complex perovskites. Although the inclusion of numerous planar defects and the oxidizable atomic defects led to significant p-type conduction and inhomogeneous electrical microstructures, resulting in an extraordinarily high extrinsic dielectric loss for the high-pressure shifted Ba8ZnTa6O24 pellet, the intrinsically near-zero τf could make the shifted Ba8ZnTa6O24 perovskite an ideal microwave dielectric resonator candidate if the defects could be eliminated.

Alpine tundra’s harsh conditions challenge plants, but Rhododendron’s adaptive mechanisms remain unclear. This study explored phenotypic/transcriptomic adaptations of three Rhododendron species (R. aureum, R. lapponicum, R. redowskianum) in Changbai Mountains’ tundra vs. timberline. Mature leaves were sampled for leaf length and leaf width measurement and RNA-seq. Results showed leaf width (not leaf length uniformly) reduced in tundra across all species. RNA-seq identified 2399–5716 DEGs per species; plant dwarfism DEGs (e.g., DELLA, EDS1) were up-regulated. Shared DEGs were enriched in carbon/nitrogen metabolism and stress response; IPUT1 (DUH022406.1) and PGT1 (DUH001929.1) were consistently down-regulated (linked to dwarfism). Species-specific responses included R. aureum’s light adaptation, R. lapponicum’s freezing/hypoxia response, and R. redowskianum’s sugar/UV/microbial regulation. Rhododendron adapts to tundra via leaf width adjustment, metabolic optimization, and IPUT1/PGT1-mediated dwarfism, with conserved core mechanisms and species specialization, supporting climate change response predictions and conservation.

In the context of climate change, Rhododendron species are pivotal in sustaining the stability of alpine ecosystems. Within alpine tundra (elevation > 2200 m) and timberline (elevation ~ 2000 m) regions of Changbai Mountain, the three studied Rhododendron species (Rhododendron aureum, Rhododendron lapponicum, and Rhododendron redowskianum) are prevalent; their mechanisms of adaptation to high-altitude environments remain insufficiently understood. This study employed an integrative approach, combining soil chemical analysis, physiological assessments, and molecular evolutionary analysis, to investigate phenotypic plasticity and genetic adaptation of these Rhododendron species. Both habitats demonstrated oligotrophic characteristics, with no significant differences (p > 0.05) observed in the concentrations of soil total organic carbon (TOC), ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), and available phosphorus (AP). Nonetheless, soil nutrient variability was more marked in timberline. Physiological traits, including malondialdehyde (MDA), soluble sugar, proline, and soluble protein, exhibited species-specific patterns; for example, R. redowskianum displayed elevated proline content in the timberline habitat, although no consistent inter-habitat trends were identified. From a total of 1995 orthogroups analysed, we identified 279 positively selected genes (PSGs, dN/dS > 1). These genes were found to be enriched in GO terms associated with DNA replication, amino acid transport, and pathway of nucleocytoplasmic transport. The study highlights tissue development and reproduction as primary evolutionary trajectories, while identifying cold stress as a significant environmental selection pressure. This research elucidates Rhododendron’s alpine adaptability and provides insights into alpine plant adaptation mechanisms and species conservation under climate change.

Using mean-field approaches within the extended five-orbital Hubbard model, we reveal that intersite Coulomb interactions play a crucial role in determining the distinct magnetic phases of iron-based superconductors. We demonstrate that the reentrant tetragonal (C4) phase, which is a spin charge density wave (SCDW) phase, is a combination of the stripe-like antiferromagnetic phase (str-AFM) and the charge density wave (CDW) phase. We prove that SCDW is the ground state in the hole-doped Fe-pnictides as long as the intersite Coulomb interaction (V) increases with doping concentration. Our work not only provides a numerical realization of the reentrant C4 state but also emphasizes the significant role of intersite interactions in the emergence of this phase, offering a deep understanding into the complex diagram phase of iron-based materials.

Fe-based mixed phosphate Na4Fe3(PO4)2P2O7 is a promising sodium-ion battery cathode due to its structural stability and cost-effectiveness, yet its capacity is limited by impurity phases and insufficient Fe redox activity. We introduce an electroactive coefficient (η = C/I), where C is the number of redox couples and I is the number of transferred ions per formula unit, as a design metric for high-capacity cathodes. Analysis reveals that Na4Fe3(PO4)2P2O7 has a suboptimal η (0.72), prompting a V-doping strategy to enhance multielectron transfer, raising η to 0.85. V doping also triggers a high-spin-to-low-spin transition in Fe2+, shortening Fe-O bonds and increasing the Fe-vacancy formation energy, thus suppressing impurities. The optimized Na3.6Fe2.6V0.4(PO4)2P2O7 achieves a record capacity of 124.6 mAh g-1 at 0.1 C. This work elucidates phase-pure cathode formation and establishes a universal design principle for high-capacity electrodes.

Low dimensional materials usually bring about unique physical properties and exceptional phenomena. Beyond the highly sought-after two-dimensional materials, the quasi-one-dimensional (1D) materials have attracted increasing attention due to the further reduced dimensionality and the resultant more pronounced quantum confinement effect. In the present Letter, we systematically explore the stability, mechanical properties, electronic structure, and optical properties of the 1D single-chain ternary bismuth subhalides Bi4RuX2 (X = I, Br) by first-principles calculations. 1D Bi4RuX2 exhibit good dynamical, thermal, and mechanical stability. Along with the dimensionality reduction from three-dimensional bulk to 1D single-chain, Bi4RuX2 undergo a transition from the indirect bandgap semiconductor to direct bandgap semiconductor, and their bandgap values increase from 1.028 and 1.151 eV to 1.224 and 1.263 eV, respectively. More importantly, 1D Bi4RuI2 and Bi4RuBr2 possess very high electron mobilities of 416.25 and 277.17 cm2 V−1 s−1, which far outperform the hole mobilities of 0.95 and 1.35 cm2 V−1 s−1. In addition, the bandgap values and band edge positions can be effectively modulated by the tensile strains, which meet the conditions for photocatalytic water splitting during a wide strain range. Furthermore, the 1D Bi4RuX2 exhibit an excellent light absorption ability of ∼105 cm−1, which can be regulated by the tensile strain for the highly efficient utilization of solar energy. The excellent electronic and optical properties indicate 1D Bi4RuX2 are promising materials for potential applications in high-performance nanoelectronic, optoelectronic devices, photocatalytic water splitting, and solar energy conversion.

Highly sensitive and reusable sensors for detecting harmful gas molecules are particularly important to reduce their harmful impacts on human health and the natural environment. Based on the density functional theory calculations, the adsorption properties and sensing performances of the monolayer penta-HgO2 material for nitrogen-containing toxic gas molecules (N2O, NH3, NO2, and NO) were thoroughly explored. The adsorptions of NH3, NO2, and NO (N2O) on the monolayer penta-HgO2 substrate are characterized by high (low) adsorption energy, significant (little) charge transfer, and short (long) adsorption distance, showing chemisorption (physisorption) properties. In addition, the band gap of penta-HgO2 decreases significantly after adsorbing NO2 and NO, resulting in a substantial increase in electrical conductivity. Meanwhile, due to the adsorption of NO, the substrate also generates an obvious magnetic moment. In this study, an efficient strategy to predict the direction and extent of charge transfer between the absorbed gas and substrate material is put forward by comparing the Fermi level and band edge positions of the adsorbent to the frontier molecular orbitals of the adsorbate. Furthermore, we propose a highly efficient resistive gas sensor based on the penta-HgO2 monolayer material for detecting NO2 and NO due to the obvious variations of the electronic structure and resultant prominent changes in the conductivity. Particularly, a Schottky diode sensor by fabricating a contacted interface between the penta-HgO2 monolayer and an Ag metal is designed according to the significantly changed work functions. The types and barrier heights of the metal-semiconductor contact (Ag-HgO2) are modulated by the adsorption of NO2 or NO. Different current signals can be observed when a bias voltage of 0.4 eV is applied, enabling the selective identification of NO2 and NO. Additionally, the short recovery time after adsorbing NO2 and NO demonstrates the reusability of the sensor. The theoretical results of this study provide valuable insights for accelerating the discovery of potential sensing materials and promote innovative resistive sensors or Schottky diode sensors based on the pentagonal monolayer material for detecting nitrogen-containing gases.

Semiconductors with a suitable band gap and high carrier mobility are highly desirable in the electronics, optoelectronic and photovoltaic applications. The mechanical, electronic, optical and transport properties of the layered nitrides ATiN(2) (A = Ca, Sr, and Ba) have been systematically studied by theoretical calculations. These nitrides show good ductility with moderate moduli, larger Poisson's ratio than 0.26 and Pugh's modulus ratio exceeding 1.75. CaTiN2 and SrTiN2 are direct bandgap semiconductors, while BaTiN2 is an indirect bandgap semiconductor, showing suitable band gaps (1.54-1.78 eV) and band edge positions for optoelectronic and photocatalytic water-splitting applications. More intriguingly, they possess superhigh carrier mobility with remarkable anisotropy. Particularly, the in-plane electron mobility reaches an ultrahigh order of 10(4) cm(2)V(-1)s(-1), whereas those along the out-of-plane direction are almost zero. In addition, the hole mobilities are also very large along the in-plane direction and the anisotropic ratios are as high as about 30 for all these nitrides. Furthermore, these ATiN(2) nitrides exhibit high optical absorption coefficients (similar to 10(5) cm(-1)) and lower exciton binding energies. Due to the suitable band gaps and band alignments, ultrahigh carrier mobility and huge anisotropy, excellent visible light absorption performance, the ATiN(2) nitrides will be promising candidate semiconductors in electronics, optoelectronic, photovoltaic and photocatalytic applications.

Plants adapt to cold stress through a tightly regulated process involving metabolic reprogramming and tissue remodeling to enhance tolerance within a short timeframe. However, the precise differences and interconnections among various organs during cold adaptation remain poorly understood. This study employed dynamic transcriptomic and metabolite quantitative analyses to investigate cold adaptation and subsequent de-adaptation in Artemisia annua, a species known for its robust resistance to abiotic stress. Our findings revealed distinct expression patterns in most differentially expressed genes (DEGs) encoding transcription factors and components of the calcium signal transduction pathway within the two organs under cold stress. Notably, the long-distance transport of carbon sources from source organs (leaves) to sink organs (roots) experienced disruption followed by resumption, while nitrogen transport from roots to leaves, primarily in the form of amino acids, exhibited acceleration. These contrasting transport patterns likely contribute to the observed differences in cold response between the two organs. The transcriptomic analysis further indicated that leaves exhibited increased respiration, accumulated anti-stress compounds, and initiated the ICE-CBF-COR signaling pathway earlier than roots. Differential expression of genes associated with cell wall biosynthesis suggests that leaves may undergo cell wall thickening while roots may experience thinning. Moreover, a marked difference was observed in phenylalanine metabolism between the two organs, with leaves favoring lignin production and roots favoring flavonoid synthesis. Additionally, our findings suggest that the circadian rhythm is crucial in integrating temperature fluctuations with the plant’s internal rhythms during cold stress and subsequent recovery. Collectively, these results shed light on the coordinated response of different plant organs during cold adaptation, highlighting the importance of inter-organ communication for successful stress tolerance.

In many Ce-based superconductors, superconducting (SC) phases emerge or can be tuned in proximity to the antiferromagnetic (AF) quantum critical point (QCP), but so far the explicit phase evolution near the QCP lack theoretical understanding. Here, by combing the density functional theory plus dynamical mean-field theory (DFT+DMFT) with effective-model calculations, we provide a theoretical description for Ce-based superconductors under compression. DFT+DMFT calculations for the normal states reveal that the Kondo hybridizations are significantly enhanced under compression, while the initially localized $f$ electrons become fully itinerant via localized-itinerant crossover. We then construct an effective model and show that with the extracted Kondo coupling and RKKY exchange strengths from first-principle calculations, the ground-state phases of these materials can be properly predicted. We also show that the coexistence of magnetic correlation and Kondo hybridization can drive AF+SC coexisting state in narrow compression region. Under compression, competition between Kondo and RKKY interactions can drive successive transitions, from AF phase to AF+SC coexisting phase, then to paramagnetic SC phase via an AF transition which generates the QCP, and finally to normal Kondo paramagnetic (KP) phase through an SC-KP transition induced by the localized-itinerant crossover. Our study gives proper explanation to the pressure-induced QCP and SC-KP transition, and to the phase evolution in pressured Ce-based superconductors, and can help to understand the SC states around the ferromagnetic quantum transition points in uranium-based superconductors.

Recently, signatures of superconductivity with critical temperature from 20 to 30 K have been reported in pressured trilayer nickelate La$_4$Ni$_3$O$_{10}$ through a pressure-induced structure transition. Here we explore the evolution of electronic structures and electronic correlations in different phases of La$_4$Ni$_3$O$_{10}$ under corresponding pressure regions, by using density functional theory (DFT) combined with dynamical mean-field theory (DMFT). Similar to bilayer superconductor La$_3$Ni$_2$O$_{7}$, the electronic bands in superconducting La$_4$Ni$_3$O$_{10}$ are dominated by Ni-3$d_{x^2-y^2}$ and 3$d_{z^2}$ orbits near the Fermi level, in contrast, the inner Ni-O plane in La$_4$Ni$_3$O$_{10}$ generates a doublet hole-pocket Fermi surfaces around the Brillouin-zone corner, meanwhile one branch of the Ni-$3d_{z^2}$ bands is pushed very close above the Fermi level, which can induce an electron pocket through small electron doping. The DFT+DMFT simulations suggest that the electronic correlations only give minor modification to the Fermi surfaces, meanwhile the Ni-$3d_{z^2}$ and 3$d_{x^2-y^2}$ states on outer Ni-O layers have considerable greater mass enhancements than on the inner layer. The sensitiveness of electronic structure under doping and unique layer dependence of correlation suggest a distinct superconducting mechanism with respect to bilayer La$_3$Ni$_2$O$_{7}$. Based on the DFT and DFT+DMFT simulations, we eventually derive a trilayer effective tight-binding model, which can produce rather precise electronic bands and Fermi surfaces, hence can serve as an appropriate model to further study the superconducting mechanism and paring symmetry in trilayer La$_4$Ni$_3$O$_{10}$.

Using first-principle calculations, we investigate the electronic, topological and superconducting properties of Nb$_3$X (X = Ge, Sn, Sb) and Ta$_3$Y (Y = As, Sb, Bi) A15 compounds. We demonstrate that these compounds host Dirac surface states which are related to a nontrivial Z$_2$ topological value. The spin-orbit coupling (SOC) splits the eightfold degenerate R point close to the Fermi level enhancing the amplitude of the spin Hall conductance. Indeed, despite the moderate spin-orbit of the Nb-compounds, a large spin Hall effect is also obtained in Nb$_3$Ge and Nb$_3$Sn compounds. We show that the Coulomb interaction opens the gap at the R point thus making more evident the occurrence of Dirac surface states. We then investigate the superconducting properties by determining the strength of the electron-phonon BCS coupling. The evolution of the critical temperature is tracked down to the 2D limit indicating a reduction of the transition temperature which mainly arises from the suppression of the density of states at the Fermi level. Finally, we propose a minimal tight-binding model based on three coupled Su-Schrieffer-Heeger chains with t$_{2g}$ Ta- and Nb-orbitals reproducing the spin-orbit splittings at the R point among the $\pi$-bond bands in this class of compounds. We separate the kinetic parameters in $\pi$ and $\delta$-bonds, in intradimer and interdimer hoppings and discuss their relevance for the topological electronic structure. We point out that Nb$_3$Ge might represent a Z$_2$ topological metal with the highest superconducting temperature ever recorded.

Thermodynamically-stable layered cation-ordered 2D-like nitrides can be synthesized using kinetically-limited thin-film deposition methods.

Mixed oxide ion–proton conduction and the cooperative ionic migration mechanism in isolated tetrahedral LaVO 4 by acceptor doping strategies.