An insulating doped antiferromagnet with low magnetic symmetry as a room temperature spin conduit

Andrew Ross; Romain Lebrun; Lorenzo Baldrati; Akashdeep Kamra; Olena Gomonay; Shilei Ding; Felix Schreiber; Dirk Backes; Francesco Maccherozzi; Daniel A. Grave; Avner Rothschild; Jairo Sinova; Mathias Kläui

doi:10.1063/5.0032940

arXiv · 2011.09755

An insulating doped antiferromagnet with low magnetic symmetry as a room temperature spin conduit

Andrew Ross·Romain Lebrun·Lorenzo Baldrati·Akashdeep Kamra·Olena Gomonay·Shilei Ding·Felix Schreiber·Dirk Backes·Francesco Maccherozzi·Daniel A. Grave·Avner Rothschild·Jairo Sinova·Mathias Kläui

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Abstract

We report room temperature long-distance spin transport of magnons in antiferromagnetic thin film hematite doped with Zn. The additional dopants significantly alter the magnetic anisotropies, resulting in a complex equilibrium spin structure that is capable of efficiently transporting spin angular momentum at room temperature without the need for a well-defined, pure easy-axis or easy-plane anisotropy. We find intrinsic magnon spin-diffusion lengths of up to 1.5 {\mu}m, and magnetic domain governed decay lengths of 175 nm for the low frequency magnons, through electrical transport measurements demonstrating that the introduction of non-magnetic dopants does not strongly reduce the transport length scale showing that the magnetic damping of hematite is not significantly increased. We observe a complex field dependence of the non-local signal independent of the magnetic state visible in the local magnetoresistance and direct magnetic imaging of the antiferromagnetic domain structure. We explain our results in terms of a varying and applied-field-dependent ellipticity of the magnon modes reaching the detector electrode allowing us to tune the spin transport.

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Andrew Ross, Romain Lebrun, Lorenzo Baldrati, Akashdeep Kamra, Olena Gomonay, Shilei Ding, Felix Schreiber, Dirk Backes, Francesco Maccherozzi, Daniel A. Grave, Avner Rothschild, Jairo Sinova, Mathias Kläui. 2020-11-19. An insulating doped antiferromagnet with low magnetic symmetry as a room temperature spin conduit. https://doi.org/10.1063/5.0032940

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