Electrical spin injection and detection at Al$-2$O$_3$/$n$-type germanium interface using three terminal geometry

A. Jain (1) , L. Louahadj (1) , J. Peiro (2) , J. C. Le Breton (2) , C. Vergnaud (1) , A. Barski (1) , C. Beigne (1) , L. Notin (1) , A. Marty (1) , Vincent Baltz (3) , S. Auffret (3) , E. Augendre (4) , H. Jaffres (2) , J. M. George (2) , M. Jamet (1)

1 NM - Nanostructures et Magnétisme
2 Laboratoire Albert Fert (ex-UMPhy Unité mixte de physique CNRS/Thales)
3 SPINTEC - SPINtronique et TEchnologie des Composants
4 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information

In this letter, we report on electrical spin injection and detection in n-type germanium-on-insulator using a Co/Py/Al$-2$O$_3$ spin injector and 3-terminal non-local measurements. We observe an enhanced spin accumulation signal of the order of 1 meV consistent with the sequential tunneling process via interface states in the vicinity of the Al$-2$O$_3$/Ge interface. This spin signal is further observable up to 220 K. Moreover, the presence of a strong $inverted$ Hanle effect points out the influence of random fields arising from interface roughness on the injected spins.

Mots clés: Germanium; Elemental semiconductors; Ozone; Doping; Schotty barriers

Domaines: Matière Condensée [cond-mat]

A. Jain, L. Louahadj, J. Peiro, J. C. Le Breton, C. Vergnaud, et al.. Electrical spin injection and detection at Al$-2$O$_3$/$n$-type germanium interface using three terminal geometry. Applied Physics Letters, 2011, 99, pp.162102. ⟨10.1063/1.3652757⟩. ⟨hal-01683844⟩