Giant topological longitudinal circular photo-galvanic effect in the chiral multifold semimetal CoSi.

ABSTRACT: The absence of mirror symmetry, or chirality, is behind striking natural phenomena found in systems as diverse as DNA and crystalline solids. A remarkable example occurs when chiral semimetals with topologically protected band degeneracies are illuminated with circularly polarized light. Under the right conditions, the part of the generated photocurrent that switches sign upon reversal of the light's polarization, known as the circular photo-galvanic effect, is predicted to depend only on fundamental constants. The conditions to observe quantization are non-universal, and depend on material parameters and the incident frequency. In this work, we perform terahertz emission spectroscopy with tunable photon energy from 0.2 -1.1 eV in the chiral topological semimetal CoSi. We identify a large

SUBMITTER: Ni Z 

PROVIDER: S-EPMC7794406 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature