Probing the chiral anomaly with nonlocal transport in three dimensional topological semimetals

By S. Parameswaran, T. Grover, D. Abanin, D. Pesin, Ashvin Vishwanath. 2013

331 citations recorded by the source corpus.

Weyl semimetals are three-dimensional crystalline systems where pairs of bands touch at points in momentum space, termed Weyl nodes, that are characterized by a definite topological charge: the chirality. Consequently, they exhibit the Adler-Bell-Jackiw anomaly, which in this condensed matter realization implies that application of parallel electric ($\mathbf{E}$) and magnetic ($\mathbf{B}$) fields pumps electrons between nodes of opposite chirality at a rate proportional to $\mathbf{E}\cdot\mathbf{B}$. We argue that this pumping is measurable via nonlocal transport experiments, in the limit of weak internode scattering. Specifically, we show that as a consequence of the anomaly, applying a local magnetic field parallel to an injected current induces a valley imbalance that diffuses over long distances. A probe magnetic field 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 field are orthogonal, and therefore serves as a test of the chiral anomaly. We further demonstrate that a similar effect should also characterize Dirac semimetals --- recently reported to have been observed in experiments --- where a pair of Weyl nodes coexisting at a single point in the Brillouin zone are protected by a crystal symmetry. Since the nodes are analogous to valley degrees of freedom in semiconductors, this suggests that valley currents in three dimensional topological semimetals can be controlled using electric fields, which has potential practical `valleytronic' applications.

Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/0e24a8e5a47a5c8cf38d6d39de73a562d156887c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

1. Ashvin Vishwanath
2. N. P. Armitage
3. E. Mele
4. Claudia Felser
5. Ling Lu
6. Binghai Yan
7. X. Dai
8. Liang Fu

In Condensed Matter Physics

1. Ashvin Vishwanath
2. N. P. Armitage
3. E. Mele
4. H. Weng
5. X. Dai
6. Claudia Felser
7. Z. Fang
8. Binghai Yan

In Materials Chemistry

1. Ashvin Vishwanath
2. N. P. Armitage
3. E. Mele
4. Claudia Felser
5. Binghai Yan
6. J. Moore
7. X. Dai
8. Z. Fang

Citations in the corpus

• Experimental observation of Weyl points (2015, background): “[13] SA Parameswaran, T Grover, DA Abanin, DA Pesin, and A Vishwanath, “Probing the chiral anomaly with nonlocal transport in three-dimensional topological semimetals,” Physical Review X 4, 031035 (2014).”
• Fermi-arc diversity on surface terminations of the magnetic Weyl semimetal Co3Sn2S2 (2019, background): “y curvature associated with Weyl and Dirac nodes have been shown to result in unique phenomenology, most notably the chiral anomaly in magneto-transport (9-11) and various non-local transport effects (12, 13). The formation of Fermi-arcs is guaranteed by the existence of bulk Weyl nodes, and therefo”
• Experimental discovery of Weyl semimetal TaAs (2015, background): “Another unique property of a WSM is the chiral anomaly (23-25), which implies the apparent violation of charge conservation and leads to interesting transport properties, such as negative magneto-resistance, chiral magnetic effects and anomalous Hall effect (26-28).”
• Weyl and Dirac semimetals in three-dimensional solids (2017, background): “Impurities can scatter between these states and even spherically symmetric impurities induce some degree of mixing (Parameswaran et al., 2014), but ab-initio and other studies of the role of impurities should be further explored.”
• Quantized circular photogalvanic effect in Weyl semimetals (2016, background): “In practice, disorder will introduce a finite scattering rate 1/τ and the linear growth of current can only be observed for times t < τ , which in existing Weyl semimetals is τ ∼1 ps [23, 44].”
• Inhomogeneous Weyl and Dirac Semimetals: Transport in Axial Magnetic Fields and Fermi Arc Surface States from Pseudo-Landau Levels (2016, background): “The second term on the right-hand side is a scattering term that acts to equilibrate the number density ns of the left and right chiralities [89,90] with a typical scattering time τ [91].”
• Ultrahigh mobility and giant magnetoresistance in the Dirac semimetal Cd3As2. (2014, background): “In Dirac semimetals, there is strong interest in whether the chiral term (e(3)/4π(2)~(2))E ·H can be detected as a negative contribution to the longitudinal MR (E||H), with E the electric field (see SI) [10, 11, 15, 16, 29].”
• Observation of the Chiral-Anomaly-Induced Negative Magnetoresistance in 3D Weyl Semimetal TaAs (2015, background): “, the anomalous Hall effect and the nonlocal transport properties [5,12].”