Large spin accumulation voltages in epitaxial Mn5Ge3 contacts on Ge without oxide tunnel barrier

Abstract

Spin injection in high-quality epitaxial Mn5Ge3 Schottky contacts on n-type Ge has been investigated using a three-terminal Hanle effect measurement. Clear Hanle and inverted Hanle signals with features characteristic of spin accumulation and spin precession are observed up to 200 K. Strikingly, the observed spin voltage is several orders of magnitude larger than predicted by the theory of spin injection and diffusive spin transport. Since the devices have no oxide tunnel barrier, the discrepancy between theory and experiments cannot be explained by the often-invoked spin accumulation in localized states associated with the oxide or oxide/semiconductor interface. The observed spin voltages therefore must originate from the Ge itself, either from spins in the Ge bulk bands or its depletion region.

arXiv commentRelated to the submission by R. Jansen et al., arXiv:1410.3994 (2014)

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Cited by in corpus (5)

• Room-temperature spin transport in n-Ge probed by four-terminal nonlocal measurements
• Electrical detection of spin-polarized current in topological insulator Bi1.5Sb0.5Te1.7Se1.3
• Non-linear spin transport in a rectifying ferromagnet/semiconductor Schottky contact
• On the origin of the giant spin detection efficiency in tunnel barrier based electrical spin detector
• Lateral Mn5Ge3 spin-valve in contact with a high-mobility Ge two-dimensional hole gas