Chiral magnetic effect in ZrTe5

• Published in: Nature physics Vol. 12; no. 6; pp. 550 - 554
• Main Authors: Li, Qiang, Kharzeev, Dmitri E., Zhang, Cheng, Huang, Yuan, Pletikosić, I., Fedorov, A. V., Zhong, R. D., Schneeloch, J. A., Gu, G. D., Valla, T.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.06.2016; Nature Publishing Group; Nature Publishing Group (NPG)
• Subjects: 140/146; 639/766/119/995; 639/766/387/1129; 639/766/419/1133; 639/766/483/640; Atomic; Classical and Continuum Physics; Complex Systems; Condensed Matter Physics; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Electric currents; Electric properties; electronic properties and materials; letter; Magnetic fields; MATERIALS SCIENCE; Mathematical and Computational Physics; Molecular; Optical and Plasma Physics; Particle physics; Physics; Spectroscopy; Theoretical; theoretical nuclear physics; theoretical particle physics; theoretical physics; Zirconium
• ISSN: 1745-2473; 1745-2481
• DOI: 10.1038/nphys3648

A magnetotransport study of zirconium pentatelluride now reveals evidence for a chiral magnetic effect, a striking macroscopic manifestation of the quantum and relativistic nature of Weyl semimetals. The chiral magnetic effect is the generation of an electric current induced by chirality imbalance in the presence of a magnetic field. It is a macroscopic manifestation of the quantum anomaly 1 , 2 in relativistic field theory of chiral fermions (massless spin 1/2 particles with a definite projection of spin on momentum)—a remarkable phenomenon arising from a collective motion of particles and antiparticles in the Dirac sea. The recent discovery 3 , 4 , 5 , 6 of Dirac semimetals with chiral quasiparticles opens a fascinating possibility to study this phenomenon in condensed matter experiments. Here we report on the measurement of magnetotransport in zirconium pentatelluride, ZrTe 5 , that provides strong evidence for the chiral magnetic effect. Our angle-resolved photoemission spectroscopy experiments show that this material’s electronic structure is consistent with a three-dimensional Dirac semimetal. We observe a large negative magnetoresistance when the magnetic field is parallel with the current. The measured quadratic field dependence of the magnetoconductance is a clear indication of the chiral magnetic effect. The observed phenomenon stems from the effective transmutation of a Dirac semimetal into a Weyl semimetal induced by parallel electric and magnetic fields that represent a topologically non-trivial gauge field background. We expect that the chiral magnetic effect may emerge in a wide class of materials that are near the transition between the trivial and topological insulators.