Marcello Porta (SISSA): Anomaly non-renormalization in interacting Weyl semimetals
Ort: MPI für Mathematik in den Naturwissenschaften Leipzig, , Videobroadcast
Video broadcast: Webinar “Analysis, Quantum Fields, and Probability” Weyl semimetals are three-dimensional condensed matter systems characterized by a degenerate Fermi surface, consisting of a pair of `Weyl nodes'. Correspondingly, in the infrared limit, these systems behave effectively as Weyl fermions in 3+1 dimensions. As predicted by Nielsen and Ninomiya in 1983, when exposed to electromagnetic fields these materials are expected to simulate the axial anomaly of QED, by giving rise to a net quasi-particle flow between Weyl nodes. We consider a class of interacting lattice models for Weyl semimetals and prove that the quadratic response of the quasi-particle flow is universal, and equal to the chiral triangle graph of QED. Universality is the counterpart of the Adler-Bardeen non-renormalization property of the axial anomaly for QED, in a condensed matter setting. Our proof relies on the rigorous Wick rotation for real-time transport coefficients, on constructive bounds for Euclidean ground state correlations, and on lattice Ward Identities. Joint work with A. Giuliani and V. Mastropietro. <br /><br /><p><b>Webinar links and passwords and program updates will be distributed via email. If you would like to be added to the mailing list, please sign up for the mailing list at https://lists.uni-leipzig.de/mailman/listinfo/aqfp_announcements</a>.</b></p>
Beginn: Jan. 14, 2021, 5 p.m.
Ende: Jan. 14, 2021, 6 p.m.