报告题目：Chiral Magnetic Effect in Condensed Matters

报 告 人：Qiang Li，Condensed Matter Physics and Materials Science Division，Brookhaven National Laboratory, Upton, New York, 11973-5000

报告时间：2017年6月2日上午10：30

报告地点：理科楼C302

报告摘要：Recent discoveries of new phenomena due to interacting Dirac fermions across vastly different energy and length scales have led to a fascinating convergence between condensed matter physics and high energy nuclear physics. Dirac/Weyl semimetals have a linear dispersion that leads to the electrons near the Fermi energy behaving like Dirac fermions. Relativistic quantum field theory of Dirac fermions in 3D exhibits so-called chiral anomaly, which is the non-conservation of chiral charge induced by the external gauge fields with non-trivial topology. A consequence of the chiral anomaly is the chiral magnetic effect – the generation of electric current in an magnetic field induced by the chirality imbalance between the left-handed and the right-handed fermions. While it is currently under intense study at RHIC in BNL and at LHC in CERN, the chiral magnetic effect was discovered in Dirac semimetal ZrTe₅in 2014 [Q. Li, et al. arXive:1412.6542 (2014), Nature Physics 12 550 (2016)]. The powerful notion of chirality, originally discovered in high-energy and nuclear physics, underpins a wide palette of new and useful phenomena. In this presentation, I shall discuss the chiral magnetic effect from quark-gluon plasma to Dirac/Weyl semimetals, with an emphasis in condensed matter systems explored experimentally. In addition, I shall briefly accentuate the similarities and differences between the chiral magnetic effect and superconductivity. Although both the chiral magnetic effect and superconductivity are quantum phenomena that do not break time reversal symmetry, the underlying physics is very different. The chiral magnetic effect can support nearly non-dissipative charge transport without any condensates in the ground state, thus, can be potentially more robust and survive to much higher temperatures than superconducting condensates that are more easily destroyed by thermal fluctuations.