Evidence for the chiral anomaly in the Dirac semimetal Na₃Bi

Jun Xiong; Satya K Kushwaha; Tian Liang; Jason W Krizan; Max Hirschberger; Wudi Wang; R J Cava; N P Ong

doi:10.1126/science.aac6089

Evidence for the chiral anomaly in the Dirac semimetal Na₃Bi

Science. 2015 Oct 23;350(6259):413-6. doi: 10.1126/science.aac6089. Epub 2015 Sep 3.

Authors

Jun Xiong¹, Satya K Kushwaha², Tian Liang¹, Jason W Krizan², Max Hirschberger¹, Wudi Wang¹, R J Cava², N P Ong³

Affiliations

¹ Department of Physics, Princeton University, Princeton, NJ 08544, USA.
² Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
³ Department of Physics, Princeton University, Princeton, NJ 08544, USA. npo@princeton.edu.

PMID: 26338798
DOI: 10.1126/science.aac6089

Abstract

In a Dirac semimetal, each Dirac node is resolved into two Weyl nodes with opposite "handedness" or chirality. The two chiral populations do not mix. However, in parallel electric and magnetic fields ( E: || B: ), charge is predicted to flow between the Weyl nodes, leading to negative magnetoresistance. This "axial" current is the chiral (Adler-Bell-Jackiw) anomaly investigated in quantum field theory. We report the observation of a large, negative longitudinal magnetoresistance in the Dirac semimetal Na3Bi. The negative magnetoresistance is acutely sensitive to deviations of the direction of B: from E: and is incompatible with conventional transport. By rotating E: (as well as B: ), we show that it is consistent with the prediction of the chiral anomaly.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.