The chiral anomaly, screening and low energy electron dynamics of Weyl semimetals

• Applicant: Professor Dr. Peter Lemmens
• Subject Area: Experimental Condensed Matter Physics ; Theoretical Condensed Matter Physics
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 346795687

Weyl semimetals are a recently discovered class of materials with unprecedented properties. As a three-dimensional analogue to graphene they exhibit Dirac electrons in the bulk with chiral quasiparticles and an extraordinarily large electronic mobility even at room temperature. The Dirac states also give rise to strong plasmonic effects and other interesting properties in applied magnetic and electric fields. These Adler-Bell-Jackiw or chiral anomalies are presently investigated with respect to applications as key elements of future sensorics or electronics. This proposal is devoted the investigation of chiral anomalies in TaAs using electronic Raman scattering to achieve a detailed understanding of low energy dynamics and the interplay of screening and high mobility. Our data analysis is based on the regime of collision dominated scattering which is an effective approach for systems with strong quasiparticle interactions. Furthermore we follow a microscopic modelling based on a mapping of optical conductivity to electronic Raman scattering. Our previous studies of topological insulators have shown that the derived scattering rates agree well with Dirac plasmons observed in THz absorption experiments and that the calculated spectral shape of the signal follows our theoretical approach. Our project is geared towards an improved microscopic understanding of the relevant scattering processes and the chiral anomaly inherent to Weyl semimetals.

• DFG Programme: Research Grants
• International Connection: USA
• Cooperation Partner: Professor David Schmeltzer, Ph.D.