  The interplay between ferromagnetism and topological properties of electronic
band structures leads to a precise quantization of Hall resistance without any
external magnetic field. This so-called quantum anomalous Hall effect (QAHE) is
born out of topological correlations, and is oblivious of low-sample quality.
It was envisioned to lead towards dissipationless and topologically protected
electronics. However, no clear framework of how to design such an electronic
device out of it exists. Here we construct an ultra-low power, non-volatile,
cryogenic memory architecture leveraging the QAHE phenomenon. Our design
promises orders of magnitude lower cell area compared with the state-of-the-art
cryogenic memory technologies. We harness the fundamentally quantized Hall
resistance levels in moir\'e graphene heterostructures to store non-volatile
binary bits (1, 0). We perform the memory write operation through controlled
hysteretic switching between the quantized Hall states, using nano-ampere level
currents with opposite polarities. The non-destructive read operation is
performed by sensing the polarity of the transverse Hall voltage using a
separate pair of terminals. We custom design the memory architecture with a
novel sensing mechanism to avoid accidental data corruption, ensure highest
memory density and minimize array leakage power. Our design is transferrable to
any material platform exhibiting QAHE, and provides a pathway towards realizing
topologically protected memory devices.
