Rashba effect due to the external electric field

1. May 13, 2013

Nemanja989

Hi, I am modeling structure that takes into account Rashba effect, and I am not sure what is the mechanism that causes Rashba effect to appear.

On wikipedia Rashba is described as spin-orbit interaction effect which appears because electron is orbiting around nucleus and electron see nucleus orbiting around from where we get effective magnetic field that further on interact with spin of the electron.

What confuses me is why Rashba appears after we apply external electric field on the structure? Does external field somehow polarize atoms in crystal structure and therefore electrons in conduction band "see" more clearly electric field of the nucleus from where we get Rashba effect? Or is it something else?

2. May 16, 2013

Hypersphere

Where does it say that? That is quite misleading.

Basically, one can use the traditional hand waving argument: a travelling electron will perceive electric fields as magnetic fields (which the electron spin can couple to). In the simplest case, a lone Hydrogen atom, the field is entirely due to the nucleus. This is the usual (atomic) spin-orbit interaction.

However, in more complicated structures and situations, you get several different contributions to the electric field (in addition to the nuclear field). There is, in principle, a periodic crystal potential, surface potentials, external electric field etc. For a 2D structure perpendicular to the electric field, the term due to the electric field is just called the Rashba term.