Here we show the room temperature integrated detection of the helicity of photons with 1300 nm wavelength, via spin- photodiodes based on fully epitaxial Fe/MgO/Ge(001) heterostructures. These devices convert the photon helicity in a variation of the photocurrent ({\Delta}I) for opposite orientations of the Fe magnetization. We found {\Delta}I on the order of 5.9% for 100% circularly polarized light, both in the forward and the reverse bias, with a contribution of 0.8% from the Fe dichroic light absorption and of 5.1% from the spin filtering of photo-generated carriers crossing the Fe/MgO/Ge tunneling barrier.
@article{arxiv.1105.2908,
title = {Electrical detection of optically pumped spin polarization in Ge},
author = {C. Rinaldi and M. Cantoni and D. Petti and M. Leone and N. M. Caffrey and S. Sanvito and R. Bertacco},
journal= {arXiv preprint arXiv:1105.2908},
year = {2011}
}
Comments
This paper has been withdrawn by the author due to some imperfections in the figures