Tunneling through ferromagnetic barriers on the surface of a topological insulator

TL;DR

This paper investigates how ferromagnetic barriers on topological insulators can be tuned to control electron tunneling, enabling potential applications in electronic and spintronic devices.

Contribution

It demonstrates the tunability of electron transmission through ferromagnetic barriers on topological insulators by adjusting gate voltage and magnetization, revealing control over Klein tunneling.

Findings

Klein tunneling can be manipulated or suppressed.

Transmission regions depend on barrier parameters.

Potential for novel electronic and spintronic device applications.

Abstract

We study the transmission through single and double ferromagnetic barriers on the surface of a topological insulator. By adjusting the gate voltage and magnetization oreintation, the ferromagnetic barrier can be tuned into various transmission regions, where the wavevector-dependent tunnelings are quite different. We find that the Klein tunneling can be manipulated or even be turned off. These special properties offer the possibility to control electron beams on the "topological metal". Various novel devices, such as electronic collimation, wavevector filter, magnetic and electric switchs, and wavevector-based spin valve, may be constructed based on our observed phenomena.