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.
参会期间，季威教授作为“第71分会：表面物理化学分会”指导专家组成员，参与分会学术组织工作，并受邀担任4月13日主旨报告环节主持人，组织该分会重要学术交流环节。王聪副教授作了题为“低维材料表界面磁耦合机制的理论预测”的口头报告；孔祥华教授作了题为“Rational Design of Phosphorus-Doped Single-Atom Catalysts Based on Weighted d-State Center and Geometric Descriptors”的口头报告；乔婧思教授作了题为“界面工程调控二维关联电子体系的拓扑相变与自旋转移”的口头报告；郭的坪博士作了题为“一维磁性原子链的理论设计与磁学性质研究”的快闪报告，并在会议期间获得“表面物理化学新锐奖”。
研究组博士生戴佳琦、王人宏、刘泽宇、席郭灏、朱华、宗灿波分别在会议中进行了海报展示，具体信息如下：
报告人
海报题目
戴佳琦
Kagome bands and magnetism in MoTe2-x kagome monolayers
王人宏
过渡金属氧化物单层中 Kagome 材料的高通量研究
刘泽宇
梯度应变双层石墨烯中的新奇电子晶格
席郭灏
碱金属与碱土金属介导的全氟立方烷二聚体及链状结构的分子间磁性
朱华
Kondo resonance of a carbon-centered radical in a single-molecule
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.
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