Probing wavenumbers of current-induced excitations in point-contact experiments

Abstract

We demonstrate how a mechanical point-contact technique can provide information on the wavenumber of spin waves excited by high-density electrical current in magnetic multilayers. By varying the size of point-contacts, we have been able to control the size of the excitation volume and therefore the wavelength of current-induced spin waves. This leads to a technique with in situ sensitivity to wavenumbers of current-induced excitations. Our detailed size-dependent measurements support the prediction that the excited wavelength is determined by the contact size.

Keywords:

• spin transfer torque
• giant magnetoresistance
• spin waves
• point contact

Acknowledgments

The work was supported in part by NSF Grant No. DMR-06-45377.

Disclosures

The authors report no conflicts of interest in this work.