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Publication Citation: Quantitative Studies of Spin-Momentum-Transfer-Induced Excitations in Co/Cu Multilayer Films Using Point-Contact Spectroscopy

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Author(s): William H. Rippard; Matthew R. Pufall; Thomas J. Silva;
Title: Quantitative Studies of Spin-Momentum-Transfer-Induced Excitations in Co/Cu Multilayer Films Using Point-Contact Spectroscopy
Published: February 24, 2003
Abstract: We have measured current-induced magnetic excitations in a variety of exchange-coupled Co/Cu multilayers using point-contact spectroscopy. A step in the DC resistance and corresponding peak in dV/dI are observed at a critical current Ic whose value linearly depends applied magnetic field B, in agreement with Slonczewski's theory. These features are observed for both in- and out of plane fields. Excitations in ferromagnetically-coupled films occur even without an applied field. The spin transfer efficiency is determined from the slope and intercept of Ic vs. Bapp and varied from contact-to-contact. These variations are within the range predicted by Slonczewski's theory, as bounded between the diffusive and ballistic limits for electron propagation through a point contact.
Citation: Applied Physics Letters
Volume: 82
Issue: 8
Pages: pp. 1260 - 1262
Keywords: point contact;SMT;spin excitations;spin momentum transfer;
Research Areas: Spintronics
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