Giant Zeeman shifts in the optical transitions of yttrium iron garnet thin films

authors	R. Vidyasagar, O. Alves Santos, J. Holanda, R. O. Cunha, F. L. A. Machado, P. R. T. Ribeiro, A. R. Rodrigues, J. B. S. Mendes, A. Azevedo, and S. M. Rezende
journal	APPLIED PHYSICS LETTERS
abstract	We report the observation of giant Zeeman shifts in the optical transitions of high-quality very thin films of yttrium iron garnet (YIG) grown by rf sputtering on gadolinium gallium garnet substrates. The optical absorption profile measured with magneto-optical absorption spectroscopy shows dual optical transition in the UV-visible frequency region attributed to transitions from the O-2p valence band to the Fe-3d conduction band and from the O-2p valence band to Fe-2p53d6 excitonic states at the C-symmetry point of the YIG band structure. The application of a static magnetic field of only 0.6 kOe produces giant Zeeman shifts of 100 meV in the YIG band structure and 60 meV in the excitonic states corresponding to effective g-factors on the order of 104. The giant Zeeman effects are attributed to changes in energy levels by the large exchange fields of the Fe-3d orbitals during the magnetization process.
publisher	AMER INST PHYSICS
issn	0003-6951
year published	2016
volume	109
digital object identifier (doi)	10.1063/1.4962830
web of science category	Physics, Applied
subject category	Physics