Electronic transport in ferromagnetic barriers on the surface of a topological insulator with $\delta$ doping

TL;DR

This paper studies electron transport in a ferromagnetic/normal/ferromagnetic junction on a topological insulator surface, revealing conductance oscillations influenced by Fermi energy, doping, and magnetization orientation, with implications for magnetoresistance devices.

Contribution

It introduces a model considering $ ext{delta}$ doping effects on electron transport in topological insulator-based ferromagnetic junctions, highlighting the dependence on magnetization and doping parameters.

Findings

Conductance oscillates with Fermi energy, doping position, and magnitude.

Maximum conductance occurs in parallel magnetization configuration.

Potential for new magnetoresistance device applications.

Abstract

We investigate electron transporting through a two-dimensional ferromagnetic/normal/ferromagnetic tunnel junction on the surface of a three-dimensional topological insulator with taking into $\delta$ doping account. It is found that the conductance oscillates with the Fermi energy, the position and the aptitude of the $\delta$ doping. Also the conductance depends sensitively on the direction of the magnetization of the two ferromagnets, which originate from the control of the spin flow due to spin-momentum locked. It is found that the conductance is the maximum at the parallel configuration while it is minimum at the antiparallel configuration and vice versa, which may stem from the half wave loss due to the electron wave entering through the antiparallel configuration. These characters are very helpful for making new types of magnetoresistance devices due to the practical applications.