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Journal articles
Spin memory of the topological material under strong disorder
Abstract : Robustness to disorder is the defining property of any topological state. The ultimate disorder limits to topological protection are still unknown, although a number of theories predict that even in the amorphous state a quantized conductance might yet reemerge. Here we report that in strongly disordered thin films of the topological material Sb2Te3 disorder-induced spin correlations dominate transport of charge—they engender a spin memory phenomenon, generated by the nonequilibrium charge currents controlled by localized spins. We directly detect a glassy yet robust disorder-induced magnetic signal in films free of extrinsic magnetic dopants, which becomes null in a lower-disorder crystalline state. This is where large isotropic negative magnetoresistance (MR)—a hallmark of spin memory—crosses over to positive MR, first with only one e2/h quantum conduction channel, in a weakly antilocalized diffusive transport regime with a 2D scaling characteristic of the topological state. A fresh perspective revealed by our findings is that spin memory effect sets a disorder threshold to the protected topological state. It also points to new possibilities of tuning spin-dependent charge transport by disorder engineering of topological materials.
https://hal-polytechnique.archives-ouvertes.fr/hal-03069948
Contributor : Marcin Konczykowski <>
Submitted on : Tuesday, December 15, 2020 - 4:55:04 PM
Last modification on : Friday, December 18, 2020 - 3:13:33 AM
Contributor : Marcin Konczykowski <>
Submitted on : Tuesday, December 15, 2020 - 4:55:04 PM
Last modification on : Friday, December 18, 2020 - 3:13:33 AM
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