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Event Number 3088
Thursday, November 21st, 2013
 R. G. Herb Condensed Matter Seminar
 Probing the chiral anomaly with nonlocal transport in Weyl semimetals
 Time: 10:00 am
 Place: 5310 Chamberlin
 Speaker: Dmytro Pesin, University of Utah
 Abstract: Weyl semimetals are threedimensional crystalline systems where pairs of bands touch at points in momentum
space, termed Weyl nodes, that are characterized by a deinotnite topological charge: the chirality. Consequently,
they exhibit the AdlerBellJackiw anomaly, which in this condensed matter realization implies that application of parallel electric (E) and magnetic (B) inotelds pumps electrons between nodes of opposite chirality at a rate proportional to E*B. We argue that this pumping is measurable via nonlocal transport experiments, in the limit of weak internode scattering. Speciinotcally, we show that as a consequence of the anomaly, applying a local magnetic inoteld parallel to an injected current induces a valley imbalance that diffuses over long distances. A probe magnetic inoteld can then convert this imbalance into a measurable voltage drop far from source and drain. Such nonlocal transport vanishes when the injected current and magnetic inoteld are orthogonal, and therefore serves as a test of the chiral anomaly. Since the nodes are analogous to valley degrees of freedom in semiconductors, this suggests that valley currents in Weyl semimetals can be controlled using electric inotelds, which has potential practical aEuro~valleytronicaEuroTM applications.
 Host: Perkins
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