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arXiv · 1507.04868

Spin Currents injected electrically and thermally from highly spin polarized Co$_2$MnSi

Alexander Pfeiffer·Shaojie Hu·Robert M. Reeve·Alexander Kronenberg·Martin Jourdan·Takashi Kimura·Mathias Kläui
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Abstract

We demonstrate the injection and detection of electrically and thermally generated spin currents probed in Co$_2$MnSi/Cu lateral spin valves. Devices with different electrode separations are patterned to measure the non-local signal as a function of the electrode spacing and we determine a relatively high effective spin polarization $α$ of Co$_2$MnSi to be 0.63 and the spin diffusion length of Cu to be 500 nm at room temperature. The electrically generated non-local signal is measured as a function of temperature and a maximum signal is observed for a temperature of 80 K. The thermally generated non-local signal is measured as a function of current density and temperature in a second harmonic measurement detection scheme. We find different temperature dependences for the electrically and thermally generated non-local signals, which allows us to conclude that the temperature dependence of the signals is not just dominated by the transport in the Cu wire, but that there is a crucial contribution from the different generation mechanisms, which has been largely disregarded to date.

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Alexander Pfeiffer, Shaojie Hu, Robert M. Reeve, Alexander Kronenberg, Martin Jourdan, Takashi Kimura, Mathias Kläui. 2015-07-17. Spin Currents injected electrically and thermally from highly spin polarized Co$_2$MnSi. https://doi.org/10.1063/1.4929423

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