CryoCiM: Cryogenic compute-in-memory based on the quantum anomalous Hall effect

The scaling of the already matured complementary metal-oxide-semiconductor technology is steadily approaching its physical limit, motivating the quest for a suitable alternative. Cryogenic operation offers a promising pathway toward continued improvement in computing speed and energy efficiency without aggressive scaling. However, the memory wall bottleneck of the traditional von-Neumann architecture persists even at cryogenic temperature. That is where a compute-in-memory (CiM) architecture, which embeds computing within the memory unit, comes into play. Computations within the memory unit help to reduce the expensive data transfer between the memory and the computing units. Therefore, CiM provides extreme energy efficiency that can enable lower cooling cost at cryogenic temperature. In this work, we demonstrate CryoCiM, a cryogenic compute-in-memory framework utilizing a nonvolatile memory system based on the quantum anomalous Hall effect (QAHE). Our design can perform memory read/write and universal binary logic operations (NAND, NOR, and XOR). We custom design a peripheral circuit assembly that can perform the read/write and single-cycle in-memory logic operations. The utilization of a QAHE-based memory system promises robustness against process variations, through the usage of topologically protected resistive states for data storage. CryoCiM is a major step toward utilizing exclusively cryogenic phenomena to serve the dual purpose of storage and computation with ultra-low power (∼nano-watts) operations.