Quantum limit transport and destruction of the Weyl nodes in TaAs

• DOI: 10.1038/s41467-018-04542-9
• Publication Date: 2018-06-01T15:07:52Z
• Authors: B. J. Ramshaw; K. A. Modic; Arkady Shekhter; Yi Zhang; Eun-Ah Kim; Philip J. W. Moll; Maja D. Bachmann; M. K. Chan; J. B. Betts; F. Balakirev; A. Migliori; N. J. Ghimire; E. D. Bauer; F. Ronning; R. D. McDonald
• Keywords: Weyl semimetal; Quantum limit; Landau quantization

Weyl fermions are a recently discovered ingredient for correlated states of electronic matter. A key difficulty has been that real materials also contain non-Weyl quasiparticles, and disentangling the experimental signatures proven challenging. Here we use magnetic fields up to 95 T drive semimetal TaAs far into its quantum limit, where only purely chiral 0th Landau levels occupied. We find electrical resistivity be nearly independent field 50 T: unusual conventional metals but consistent with anomaly fermions. Above observe two-order-of-magnitude increase in resistivity, indicating gap opens levels. 80 strong ultrasonic attenuation below 2 K, suggesting mesoscopically textured state These results point way inducing new matter limit semimetals.