Low-current, narrow-linewidth microwave signal generation in NiMnSb based single-layer nanocontact spin-torque oscillators

We report on thefabrication ofnano-contact spin-torque oscillators based on single layers of the epitaxiallygrown half-metal NiMnSb with ultralowspin wave damping. We demonstrate magnetization auto-oscillations atmicrowave frequencies in the 1 –3 GHz range in out-of-plane magnetic fields. Threshold current densities as low as 3 × 1011 A m−2 are observed as well as minimum oscillationlinewidths of 200  kHz, both of which are much lower than the values achieved in conventional metallic spin-valve-based devices of comparable dimensions. These results enable thefabrication of spin transfer torque driven magnonic devices with low current density requirements, improved signallinewidths, and in a simplified single-layer geometry.

Source: Applied Physics Letters - November 30, 2016 Category: Physics Authors: P. D ürrenfeld, F. Gerhard, S. M. Mohseni, M. Ranjbar, S. R. Sani, S. Chung, C. Gould, L. W. Molenkamp and J. Åkerman Source Type: research