Chiral Magnetic Effect in Condensed Matters
Speaker: Qiang Li (Brookhaven National Laboratory)
Time: June 02, 2017 10:30
Abstract: 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 ZrTe5 in 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.
Bio: Dr. Qiang Li is a Tenured Physicist at US Department of Energy’s Brookhaven National Laboratory, New York, where he is the head of Advanced
Energy Materials Group. Graduated from the University of Science and Technology of China in Hefei in 1986, he went to Iowa State University on the
CUSPEA program, and received Ph. D in Physics in 1991. Later that year, he joined the Condensed Matter Physics and Materials Science Division at
Brookhaven National Lab. His research interests range from basic physics and material science studies of quantum electronic materials to the applications
of superconductors and thermoelectrics. He is also an adjunct professor at Stony Brook University, and an elected Fellow of American Physical Society.