Spin filtering with Mn-doped Ge-core/Si-shell nanowires
Document Type
Article
Publication Date
5-1-2020
Department
Department of Physics
Abstract
Incorporating spin functionality into a semiconductor core-shell nanowire that offers immunity from the substrate effect is a highly desirable step for its application in next generation spintronics. Here, using first-principles density functional theory that does not make any assumptions of the electronic structure, we predict that a very small amount of Mn dopants in the core region of the wire can transform the Ge-Si core-shell semiconductor nanowire into a half-metallic ferromagnet that is stable at room temperature. The energy band structures reveal a semiconducting behavior for one spin direction while the metallic behavior for the other, indicating 100% spin polarization at the Fermi energy. No measurable shifts in energy levels in the vicinity of Fermi energy are found due to spin-orbit coupling, which suggests that the spin coherence length can be much higher in this material. To further assess the use of this material in a practical device setting, we have used a quantum transport approach to calculate the spin-filtering efficiency for a channel made out of a finite nanowire segment. Our calculations yield an efficiency more than 90%, which further confirms the excellent spin-selective properties of our newly tailored Mn-doped Ge-core/Si-shell nanowires.
Publication Title
Nanoscale Advances
Recommended Citation
Aryal, S.,
&
Pati, R.
(2020).
Spin filtering with Mn-doped Ge-core/Si-shell nanowires.
Nanoscale Advances,
2(5), 1843-1849.
http://doi.org/10.1039/c9na00803a
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/2699
Publisher's Statement
© The Royal Society of Chemistry 2020. Publisher’s version of record: https://doi.org/10.1039/c9na00803a