# Intrinsic quantized anomalous Hall effect in a moir\'e heterostructure

## TL;DR

This paper reports the discovery of a quantized anomalous Hall effect in twisted bilayer graphene driven by intrinsic correlations, demonstrating a robust topological state with potential for electrically controllable magnetic memory.

## Contribution

It presents the first observation of intrinsic quantized anomalous Hall effect in moiré heterostructures, showing strong correlation-driven topological order with electrical control.

## Key findings

- Hall resistance quantized to within 0.1% of h/e^2 at zero magnetic field
- Transport energy gap of approximately 27 K larger than Curie temperature
- Electrical currents as small as 1 nA can switch magnetic states

## Abstract

We report the observation of a quantum anomalous Hall effect in twisted bilayer graphene showing Hall resistance quantized to within .1\% of the von Klitzing constant $h/e^2$ at zero magnetic field.The effect is driven by intrinsic strong correlations, which polarize the electron system into a single spin and valley resolved moir\'e miniband with Chern number $C=1$. In contrast to extrinsic, magnetically doped systems, the measured transport energy gap $\Delta/k_B\approx 27$~K is larger than the Curie temperature for magnetic ordering $T_C\approx 9$~K, and Hall quantization persists to temperatures of several Kelvin. Remarkably, we find that electrical currents as small as 1~nA can be used to controllably switch the magnetic order between states of opposite polarization, forming an electrically rewritable magnetic memory.