相比铁磁体，反铁磁材料其实更有助于开发更高密度、更快运行速度的磁性存储器，但这要满足一 个条件：在保持反铁磁态的基础上，所有磁性层同时发生整体性双态切换。 记者29日从复旦大学获悉，该校物理学研究团队利用自主开发的多模态磁光显微技术，发现一类特 殊的低维反铁磁体系能够在外磁场下像铁磁体一样展现出确定性的双稳态整体切换，并完善了经典的磁 学理论框架，用来描述该现象背后的物理机制。该研究揭示了低维层间反铁磁体磁化翻转的关键因素与 独特效应，推动反铁磁材料研究迈出从"有趣而无用"到"可读可写"的关键一步，为开发新一代低功耗、 高速运算芯片提供了新路径。相关成果29日在线发表于国际学术期刊《自然》。 该研究为反铁磁动力学基础研究以及技术应用带来了变革性突破，也为未来低维磁性材料集成到自 旋电子学以及光电子领域中开辟了新途径。 在铁磁体中，磁针均整齐指向同一方向，易于通过外磁场调控，因此常规磁性设备如机械硬盘等均 以铁磁材料作为存储单元。而反铁磁材料由于磁针方向相反、磁性抵消而很难被磁场调控，多被当作辅 助铁磁体的"配角"。 (责编：罗知之、陈键) 关注公众号：人民网财经 复旦大学物理学系吴施伟所在团队基于多年的技术积 ...

Core Insights - The research team from Hebrew University of Jerusalem published a paper revealing that the magnetic field of light plays a direct role in the Faraday effect, challenging the long-held belief that only the electric field of light is significant [1][2]. Group 1: Research Findings - The study theoretically confirms that the oscillating magnetic field of light directly contributes to the formation of the Faraday effect, indicating that light can influence matter through its magnetic properties [1]. - The Faraday effect, discovered by Michael Faraday in 1845, involves the rotation of the polarization direction of light as it passes through a material in a constant magnetic field. The new research highlights the previously overlooked contribution of light's magnetic field [1]. - The research utilized the Landau-Lifshitz-Gilbert equation to conduct precise calculations, demonstrating that the magnetic field of light can induce magnetic moments within materials, similar to the effects of a static magnetic field [1]. Group 2: Experimental Predictions - Calculations predict that using magnetic materials like gadolinium gallium garnet in repeated Faraday experiments could show that the magnetic contribution of light to the Faraday effect can reach up to 17% for visible light and as high as 70% for infrared light [2]. - This finding suggests that the interaction between light and matter occurs not only through the electric field but also through the magnetic field, which has been underappreciated historically [2]. - Igor Rozhansky from the University of Manchester commented that the computational results are compelling and warrant further experimental validation, indicating potential new methods for scientists to control the internal spins of materials [2].

Core Insights - Chinese researchers have revealed a physical mechanism that significantly reduces energy consumption in spintronic devices, providing a new principle and design approach for ultra-low power devices [2][3] - The study highlights the limitations of traditional electronic technology as it approaches performance limits, with the "power wall" becoming a bottleneck for technological advancement [2] - The research indicates that the introduction of defects in materials can enhance the efficiency of spintronic devices by increasing the orbital Hall angle and orbital Hall conductivity, thus lowering write current and power consumption [3] Group 1 - The research team from the Ningbo Institute of Materials Technology and Engineering discovered that the non-traditional scaling law of electronic "orbital" properties can convert electronic motion resistance into performance gains [2] - The findings were published online in the journal Nature Materials on August 15, indicating a significant breakthrough in overcoming the performance bottlenecks of traditional spintronics [2] - The study suggests that the new generation of spintronic devices theoretically possesses advantages such as high speed and non-volatility, making them potential technologies to break through the "power wall" [2] Group 2 - The research demonstrates that crystal defects, previously seen as obstacles, can act as "fuel stations" when interacting with the orbital angular momentum of electrons, leading to stronger detected orbital effects [3] - By actively introducing defects, the study shows that both the orbital Hall angle and orbital Hall conductivity can be increased simultaneously, breaking the limitations of traditional methods [3] - This discovery not only provides a new physical basis for efficient orbital electronics but also offers a fresh design perspective for the entire field of spintronics [3]

Core Insights - Chinese researchers have revealed a physical mechanism that can significantly reduce energy consumption in spintronic devices, providing a new principle and design approach for ultra-low power devices [1][2] - The study highlights the limitations of traditional electronic technology as it approaches performance limits, with the "power wall" becoming a bottleneck for technological advancement [1] - The research indicates that the introduction of defects in materials can enhance the efficiency of spintronic devices by increasing the orbital Hall angle and orbital Hall conductivity, thus lowering write current and power consumption [2] Group 1 - The research was published in the international journal "Nature Materials" on August 15, indicating a significant academic contribution [1] - The study focuses on the interaction between electronic orbital properties and crystal defects, which were previously seen as obstacles but are now viewed as beneficial [2] - The findings suggest a new "anomalous scaling law" that allows for simultaneous optimization of key performance indicators in spintronic devices, overcoming traditional limitations [2] Group 2 - The research team from the Ningbo Institute of Materials Technology and Engineering emphasizes the potential of spintronics as a breakthrough technology to overcome the "power wall" [1] - The study provides a new physical basis for efficient orbital electronics, potentially transforming the entire field of spintronics [2] - The implications of this research could lead to advancements in high-speed, non-volatile next-generation spintronic devices [1][2]

Core Insights - The scientists at Delft University of Technology have observed quantum spin flow in graphene without the need for an external magnetic field, marking a significant breakthrough in spintronics [1] - This discovery is a crucial step towards the realization of quantum computing and advanced storage devices, as published in the latest issue of Nature Communications [1] Industry Implications - The observation of quantum spin Hall effect in graphene could accelerate advancements in spintronics, which is essential for developing next-generation electronic devices [1] - The findings may lead to enhanced performance in quantum computing technologies, potentially transforming the landscape of data processing and storage solutions [1]

Core Viewpoint - The rapid development of large language models (LLMs) is pushing the limits of contemporary computing hardware, necessitating exploration of alternative computing paradigms such as photonic hardware to meet the increasing computational demands of AI models [1][4]. Group 1: Photonic Hardware and Its Advantages - Photonic computing utilizes light for information processing, offering high bandwidth, strong parallelism, and low thermal dissipation, which are essential for next-generation AI applications [4][5]. - Recent advancements in photonic integrated circuits (PICs) enable the construction of fundamental neural network modules, such as coherent interferometer arrays and micro-ring resonator weight arrays, facilitating dense matrix multiplication and addition operations [4][5]. - The integration of two-dimensional materials like graphene and transition metal dichalcogenides (TMDCs) into silicon-based photonic platforms enhances the functionality of modulators and on-chip synaptic elements [5][31]. Group 2: Challenges in Mapping LLMs to New Hardware - Mapping transformer-based LLM architectures to new photonic hardware presents challenges, particularly in designing reconfigurable circuits for dynamic weight matrices that depend on input data [5][6]. - Achieving nonlinear functions and normalization in photonic or spintronic media remains a significant technical hurdle [5][6]. Group 3: Key Components and Technologies - Photonic neural networks (PNNs) leverage various optical devices, such as micro-ring resonators and Mach-Zehnder interferometer arrays, to perform efficient computations [9][13]. - The use of metasurfaces allows for high-density parallel optical computations by modulating light properties through sub-wavelength structured materials [14][16]. - The 4f optical systems enable linear filtering functions through Fourier transformation, integrating deep diffraction neural networks into optical architectures [20][21]. Group 4: Integration of Two-Dimensional Materials - The integration of graphene and TMDCs into photonic chips is crucial for developing high-speed and energy-efficient AI hardware, with applications in optical modulators, photodetectors, and waveguides [31][35][36]. - Graphene's exceptional optical and electronic properties, combined with TMDCs' tunable bandgap, enhance the performance of photonic devices, making them suitable for AI workloads [31][32]. Group 5: Future Directions and Challenges - The scalability of integrating two-dimensional materials poses challenges due to their fragility, necessitating advancements in transfer techniques and wafer-scale synthesis [45]. - Material stability and the complexity of integration with existing CMOS processes are critical factors that need to be addressed for widespread adoption of these technologies [45][46].