Pushing the thickness limit of the giant Rashba effect in ferroelectric semiconductor GeTe
One of our main societal challenges is to reduce the power consumption of electronic components. A recently developed approach consists of ferroelectric control of charge or spin transport. In this context, GeTe appears as a candidate with great potentialities, as its electronic band structure is characterized by a spin polarization (i) induced by a strong Rashba-type spin-orbit coupling and (ii) controllable by reversing the material ferroelectric polarization.
To date, only one study has investigated the dependence of the Rashba effect on the thickness of GeTe thin films. A decrease in this effect below 5nm has been observed, until it disappears below 3nm. As part of a collaboration between several French laboratories, we have shown, by means of angle-resolved photoemission spectroscopy measurements (ARPES) in agreement with ab initio electronic band structure calculations, that by modifying the conditions under which thin films are elaborated, a giant Rashba effect persists in 1nm-thick films. These results open up new prospects for reducing the size of low-power electronic components.
For more information :
https://doi.org/10.1021/acs.nanolett.4c03281