Two-dimensional materials with multiple degrees of freedom, including spin, valleys, and orbitals, open up an exciting avenue for engineering multifunctional devices. Beyond spintronics, these degrees of freedom can lead to novel quantum effects such as valley-dependent Hall effects and orbital magnetism, which could revolutionize next-generation electronics. However, achieving independent control over valley polarization and orbital magnetism has been a challenge due to the need for large electric fields. A recent breakthrough involving penta-layer rhombohedral graphene has demonstrated the ability to individually manipulate anomalous Hall signals and orbital magnetic hysteresis, forming what is known as a valley-magnetic quartet. Here, we leverage the electrically tunable Ferro-valleytricity of penta-layer rhombohedral graphene to develop non-volatile memory and in-memory computation applications. We propose an architecture for a dense, scalable, and selector-less non-volatile memory array that harnesses the electrically tunable ferro-valleytricity. In our designed array architecture, non-destructive read and write operations are conducted by sensing the valley state through two different pairs of terminals, allowing for independent optimization of read/write peripheral circuits. The power consumption of our PRG-based array is remarkably low, with only ~ 6 nW required per write operation and ~ 2.3 nW per read operation per cell. This consumption is orders of magnitude lower than that of the majority of state-of-the-art cryogenic memories. Additionally, we engineer in-memory computation by implementing majority logic operations within our proposed non-volatile memory array without modifying the peripheral circuitry. Our framework presents a promising pathway toward achieving ultra-dense cryogenic memory and in-memory computation capabilities.

翻译：具有自旋、谷和轨道等多自由度的二维材料为多功能器件设计开辟了激动人心的新途径。这些自由度不仅可用于自旋电子学，还能引发诸如谷依赖霍尔效应和轨道磁性等新颖量子效应，有望彻底变革下一代电子技术。然而，由于需要施加强电场，实现对谷极化和轨道磁性的独立调控一直是个挑战。近期在五层菱面体石墨烯中取得的突破性进展，展示了独立调控反常霍尔信号与轨道磁滞回线的能力，形成了所谓的谷磁四重态。本文利用五层菱面体石墨烯的电可调铁谷性，开发了非易失性存储器和存内计算应用。我们提出了一种基于电可调铁谷性的高密度、可扩展、无选通器的非易失性存储器阵列架构。在该阵列架构中，通过两组不同的终端对谷态进行检测，实现了非破坏性的读写操作，并允许读写外围电路独立优化。基于PRG的阵列功耗极低，每个存储单元的单次写入操作仅需约6 nW，单次读取操作仅需约2.3 nW，比绝大多数先进低温存储器的功耗低数个数量级。此外，我们在所提出的非易失性存储器阵列中实现了多数逻辑运算，从而构建了存内计算功能，且无需修改外围电路。该框架为实现超高密度低温存储器及存内计算能力提供了前景广阔的技术路径。