Question

 What is spin transport?

 How does spin transport behave in semiconductors?

 How does spin transport affect the conductivity in the semiconductors?

 Read the online materials and run the simulation.

 You need to specify simulation criteria.

Answer 1

1)Spin State is the study of the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, in solid-state devices.

2)Doped semiconductor materials display dilute ferromagnetism. In recent years, dilute magnetic oxides (DMOs) including ZnO based DMOs and TiO2-based DMOs have been the subject of numerous experimental and computational investigations. Non-oxide ferromagnetic semiconductor sources (like manganese-doped gallium arsenide GaMnAs),increase the interface resistance with a tunnel barrier, or using hot-electron injection.

Because external magnetic fields (and stray fields from magnetic contacts) can cause large Hall effects and magnetoresistance in semiconductors (which mimic spin-valve effects), the only conclusive evidence of spin transport in semiconductors is demonstration of spin precession and dephasing in a magnetic field non-collinear to the injected spin orientation, called the Hanle effect.

3)The spin and charge transport in materials with spin-dependent conductivity has been studied. It has been shown that there is a charge accumulation along spin diffusion in a ferromagnetic metal, which causes a shortening of the spin diffusion length. It has been shown that there is a substantial interaction between the drift and diffusion currents in semiconductors. The effects of gain/damping of a spin current by a charge current and the existence of a threshold spin current in a semiconductor have been described. Because of the substantial magnitude, these new spintronics effects might be used for new designs of efficient spintronic devices