Optical evidence of the chiral magnetic anomaly in the Weyl semimetal TaAs
Antonio Levy, A. B. Sushkov, Fengguang Liu, Bing Shen, Ni Ni, H. D. Drew, Gregory S. Jenkins
Abstract
Chiral pumping from optical electric fields oscillating at terahertz frequencies is observed in the Weyl material TaAs with electric and magnetic fields aligned along both the $a$ and $c$ axes. Free-carrier spectral weight enhancement is measured directly, confirming theoretical expectations of chiral pumping. A departure from linear field dependence of the Drude weight is observed at the highest fields in the quantum limit, providing evidence of field-dependent Fermi velocity of the chiral Landau level. Implications for the chiral magnetic effect in Weyl semimetals from the optical $f$-sum rule are discussed.
Topics & Concepts
Chiral anomalyWeyl semimetalSemimetalPhysicsMagnetic fieldCondensed matter physicsLandau quantizationAnomaly (physics)Electric fieldQuantum limitTerahertz radiationDrude modelQuantum electrodynamicsQuantumQuantum mechanicsFermionBand gapTopological Materials and PhenomenaQuantum Mechanics and Non-Hermitian Physics2D Materials and Applications