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arXiv · 1805.05955

Low-dissipation edge currents without edge states

Justin C. W. Song·Giovanni Vignale
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Abstract

We show that bulk free carriers in topologically trivial multi-valley insulators with non-vanishing Berry curvature give rise to low-dissipation edge currents, which are squeezed within a distance of the order of the valley diffusion length from the edge. This happens even in the absence of edge states [topological (gapless) or otherwise], and when the bulk equilibrium carrier concentration is thermally activated across the gap. Physically, the squeezed edge current arises from the spatially inhomogeneous orbital magnetization that develops from valley-density accumulation near the edge. While this current possesses neither topology nor symmetry protection and, as a result, is not immune to dissipation, in clean enough devices it can mimic low-loss ballistic transport.

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Justin C. W. Song, Giovanni Vignale. 2018-05-15. Low-dissipation edge currents without edge states. https://doi.org/10.1103/physrevb.99.235405

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