Experimental Demonstration of Room-Temperature Spin Transport in n -Type Germanium Epilayers
Abstract
We report an experimental demonstration of room-temperature spin transport in n -type Ge epilayers grown on a Si(001) substrate. By utilizing spin pumping under ferromagnetic resonance, which inherently endows a spin battery function for semiconductors connected with a ferromagnet, a pure spin current is generated in the n -Ge at room temperature. The pure spin current is detected by using the inverse spin-Hall effect of either a Pt or Pd electrode on n -Ge . From a theoretical model that includes a geometrical contribution, the spin diffusion length in n -Ge at room temperature is estimated to be 660 nm. Moreover, the spin relaxation time decreases with increasing temperature, in agreement with a recently proposed theory of donor-driven spin relaxation in multivalley semiconductors.
- Publication:
-
Physical Review Letters
- Pub Date:
- May 2015
- DOI:
- 10.1103/PhysRevLett.114.196602
- arXiv:
- arXiv:1501.06691
- Bibcode:
- 2015PhRvL.114s6602D
- Keywords:
-
- 72.25.Dc;
- 72.25.Mk;
- 76.50.+g;
- 85.75.-d;
- Spin polarized transport in semiconductors;
- Spin transport through interfaces;
- Ferromagnetic antiferromagnetic and ferrimagnetic resonances;
- spin-wave resonance;
- Magnetoelectronics;
- spintronics: devices exploiting spin polarized transport or integrated magnetic fields;
- Condensed Matter - Materials Science
- E-Print:
- 27 pages, 6 figures, Suppelmental Materials