# Large Anomalous Hall Effect in Topological Insulators with Proximitized   Ferromagnetic Insulators

**Authors:** Masataka Mogi, Taro Nakajima, Victor Ukleev, Atsushi Tsukazaki,, Ryutaro Yoshimi, Minoru Kawamura, Kei S Takahashi, Takayasu Hanashima,, Kazuhisa Kakurai, Taka-hisa Arima, Masashi Kawasaki, Yoshinori Tokura

arXiv: 1906.02159 · 2019-07-04

## TL;DR

This study demonstrates a significant anomalous Hall effect in heterostructures combining topological insulators with ferromagnetic insulators, driven by proximity effects that induce strong exchange coupling and open a sizable gap in surface states.

## Contribution

It reveals a large anomalous Hall effect in topological insulator heterostructures with ferromagnetic insulators due to proximity-induced exchange coupling.

## Key findings

- Anomalous Hall conductivity reaches 0.2e2/h.
- Exchange coupling effectively opens a sizable gap in surface states.
- Proximity effect induces ferromagnetic response in topological insulators.

## Abstract

We report a proximity-driven large anomalous Hall effect in all-telluride heterostructures consisting of ferromagnetic insulator Cr2Ge2Te6 and topological insulator (Bi,Sb)2Te3. Despite small magnetization in the (Bi,Sb)2Te3 layer, the anomalous Hall conductivity reaches a large value of 0.2e2/h in accord with a ferromagnetic response of the Cr2Ge2Te6. The results show that the exchange coupling between the surface state of the topological insulator and the proximitized Cr2Ge2Te6 layer is effective and strong enough to open the sizable exchange gap in the surface state.

---
Source: https://tomesphere.com/paper/1906.02159