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arXiv · 1505.04535

Evidence on the macroscopic length scale spin coherence for the edge currents in a narrow HgTe quantum well

A. Kononov·S. V. Egorov·Z. D. Kvon·N. N. Mikhailov·S. A. Dvoretsky·E. V. Deviatov
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Abstract

We experimentally investigate spin-polarized electron transport between two ferromagnetic contacts, placed at the edge of a two-dimensional electron system with band inversion. The system is realized in a narrow (8~nm) HgTe quantum well, the ferromagnetic side contacts are formed from a pre-magnetized permalloy film. In zero magnetic field, we find a significant edge current contribution to the transport between two ferromagnetic contacts. We experimentally demonstrate that this transport is sensitive to the mutual orientation of the magnetization directions of two 200~$μ$m-spaced ferromagnetic leads. This is a direct experimental evidence on the spin-coherent edge transport over the macroscopic distances. Thus, the spin is extremely robust at the edge of a two-dimensional electron system with band inversion, confirming the helical spin-resolved nature of edge currents.

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A. Kononov, S. V. Egorov, Z. D. Kvon, N. N. Mikhailov, S. A. Dvoretsky, E. V. Deviatov. 2015-05-18. Evidence on the macroscopic length scale spin coherence for the edge currents in a narrow HgTe quantum well. https://doi.org/10.1134/s0021364015120115

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