The research about two-dimensional van der Waals magnetic materials has advanced the 22 breakthroughs in ultrathin magnetic devices. We experimentally demonstrate that single-crystal 23 N-face AlN polar substrate can program layer-number-parity-dependent magnetic multistates and 24 their evolution sequence in few-layer CrI3. In odd-layer samples, as 5L-CrI3/AlN, when μ0H 25 sweeps from 3 to −3 T, the reflective magnetic circular dichroism signal evolves through distinct 26 magnetic multistates (+5 → –1 → +1 → –5), where +1 corresponds to the moment of a spin-up 27 monolayer. Thereby, we vertically program novel magnetic ground states and their evolution 28 sequence via a simplified heterointerface. Our first-principles calculations attribute this effect to 29 interfacial hole doping: it globally reconfigures the magnetic ground state of odd-layer CrI3 to a 30 novel ferrimagnetic order, and spatially differentiates the interlayer exchange and magnetic 31 anisotropy between the surface/interfacial and interior layers. Our work advances the practical 32 integration and design of two-dimensional magnetic devices with tailored functionalities.
The charge states of metal adatoms on surfaces play a crucial role in controlling adsorption and interaction behaviors that underpin surface chemistry and catalysis, yet the atomically synthesis of negatively charged metal atoms remains a significant challenge. Here, we report negatively-charged Ag dimer (Ag_2^(δ-)) arrays assembled on Ag(100) surface through coordination with a polycyclic aromatic hydrocarbon, 8,9-diaza-8a-borabenzo[fg]tetracene (DBT), featuring a doping moiety with N-B-N bonds at zigzag edge. The Ag dimers are stabilized by two DBT monomers through N-Ag-N coordination bonding. In contrast to surface Ag atoms, the coordinated dimers display anionic character, as demonstrated by non-contact atomic force microscopy, Kelvin probe force microscopy, x-ray photoelectron spectroscopy, and density functional theory calculations. Neutral dimers Ag_2^0 can be converted from the coordinated complex by tip-induced detachment of one DBT monomer, and showed markedly higher affinity for CO adsorption, a process that is suppressed on (Ag_2^(δ-)). These findings establish an atomically defined platform for stabilizing and controlling anionic metal centers on metallic surfaces, providing a model system for exploring charge-state effects in surface chemistry.
The chromium-based kagome metal CsCr3Sb5 has garnered significant interest due to its strong electron correlations, intertwined orders and potential for unconventional superconductivity under high pressure. The evolution of magnetic and superconducting interactions as the more frequently studied CsCr3Sb5 is doped to CsCr3Sb5 remains poorly understood. Here, we demonstrate the emergence of a spatially anisotropic Kondo resonance intertwined with the superconducting gap, enabled by introducing magnetic Cr impurities into the kagome superconductor CsCr3Sb5. The addition of dilute Cr impurities not only weakens long range charge density wave order but also produces local magnetic moments that leads to Kondo resonances. We show that the Kondo resonance forms anisotropic, ripple like spatial patterns around individual Cr atoms, breaking all local mirror symmetries. We further reveal that with the emergence of Kondo screening, the coherence peak and depth of superconducting gap with finite zero-energy conductance are enhanced. This suggests that non superconducting carriers at the Fermi surface in the parent compound participate in the Kondo effect, simultaneously screening Cr magnetic moments and increasing the superfluid density. Our findings offer an opportunity to study the interplay between superconductivity and local magnetism in kagome materials.
Information units are progressively approaching the fundamental physical limits of the integration density, including in terms of extremely small sizes, multistates and probabilistic traversal. However, simultaneously encompassing all of these characteristics in a unit remains elusive. Here, via real-time in situ electrical monitoring, we clearly observed stochastic alterations of multiple conductance states in Sc2C2@C88. The true random bit sequence generated exhibited an autocorrelation function whose confidence interval fell within ±0.02, demonstrating high-quality randomness. The alterations of multiple conductance states are controllable, that is, whose probability distributions could traverse from “0” to “1”, enabling us to factorize 551 into its prime factors. Furthermore, we proposed a matrix-chain multiplication scheme and experimentally verified the multiplication of two 4 × 4 state-transition matrices with a small maximum error < 0.05. Combined with theoretical calculations, the stochastic but controllable multistates are probably attributed to the rich energy landscape, which could be stepwise changed by the electric field. Our findings reveal extremely small multi-level probabilistic bit for matrix multiplication, which pave the way for ultracompact intelligent electronic devices.
Zhi-Hao Li#, Jia-Qi Dai#, Guan Luo, Ruo-Ning Li, An-Jing Zhao, Jun-Jie Duan, Yu Ge, Zi-Cong Wang, Wei Ji*, Ting Chen*, Dong Wang and Li-Jun Wan
Abstract:
Atomically thin InTe, a III–VI analogue of InSe, has recently emerged as a promising two-dimensional semiconductor for nanoelectronics, yet the nature of its two-dimensional electron gas (2DEG) has remained experimentally elusive. Here, using scanning tunneling microscopy (STM) combined with quasiparticle interference (QPI) imaging, we present direct evidence of the existence of a 2DEG in monolayer and bilayer InTe. Bias-dependent standing-wave patterns reveal a parabolic conduction-band dispersion in both thicknesses. Quantitative analysis yields a low electron effective mass of 0.241me in monolayer InTe, smaller than that of monolayer InSe/BLG (∼0.27me). In bilayer InTe, interlayer coupling lifts the conduction-band-edge degeneracy, and produces two subbands with effective masses of 0.197me and 0.802me. Density functional theory calculations are in good agreement with the experimental observations. These results establish atomically thin InTe as a promising platform for low-dimensional electronic physics and nanoelectronic applications.
Zhi-Hao Li#, Jia-Qi Dai#, Guan Luo, Ruo-Ning Li, An-Jing Zhao, Jun-Jie Duan, Yu Ge, Zi-Cong Wang, Wei Ji*, Ting Chen*, Dong Wang and Li-Jun Wan
Abstract:
As a fundamental phenomenon in nature, chirality has been extensively studied in molecular structures; however, it remains underexplored at the electronic level. Understanding how structural chirality transfers into electronic states is crucial for uncovering the essence of many chiral effects. In this study, we report the engineering and direct visualization of chiral electronic states within an otherwise planar, achiral hexa- peri -hexabenzocoronene (HBC) framework. By employing atomically precise asymmetric nitrogen doping of HBC through on-surface synthesis, we fabricate a C3 -symmetric triaza-HBC on Au(111). Utilizing high-resolution scanning tunneling microscopy and non-contact atomic force microscopy, we resolve the chiral molecular structure of triaza-HBC confined to the surface, as well as the chiral texture of the resulting interfacial electronic states and its evolution at different energies. Density functional theory calculations reveal that these electronic chiral features arise from the molecule’s intrinsic chiral orbitals, which hybridize strongly with the metal substrate while still retaining their chiral character. This study not only demonstrates a clear transfer of chirality from molecular structure to the electronic landscape but also provides a versatile platform for the rational design of chiral electronic molecules and materials.
