Evidence for the chiral anomaly in the Dirac semimetal Na₃Bi.
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.
Department of Physics, Princeton University, Princeton, NJ 08544, USA.
Jun
J
Xiong
Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
Satya K
SK
Kushwaha
Department of Physics, Princeton University, Princeton, NJ 08544, USA.
Tian
T
Liang
Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
Jason W
JW
Krizan
Department of Physics, Princeton University, Princeton, NJ 08544, USA.
Max
M
Hirschberger
Department of Physics, Princeton University, Princeton, NJ 08544, USA.
Wudi
W
Wang
Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
R J
RJ
Cava
Department of Physics, Princeton University, Princeton, NJ 08544, USA. npo@princeton.edu.
N P
NP
Ong