Year: 2019
Type: article
Abstract: We generalize the notion of a dissipationless, topological Hall viscosity tensor to optical phonons in thin-film Weyl semimetals. By using the strained porphyrin thin-film Weyl semimetal as a model example, we show how optical phonons can couple to Weyl electrons as chiral pseudogauge fields. These chiral vector fields lead to a novel dissipationless two-rank viscosity tensor in the effective dynamics of optical phonons whose origin is the chiral anomaly. We also compute the contribution to this two-rank Hall viscosity tensor due to the presence of an external magnetic field whose origin is the conventional Hall response of Weyl electrons. Finally, the phonon dispersion relations of the system at the long-wavelength limit with and without an electromagnetic field are calculated, showing a measurable shift in the Raman response of the system. Our results can be investigated by Raman scattering or infrared spectroscopy by attenuated total reflectance experiments.
Authors: Shiva Heidari, Alberto Cortijo, Reza Asgari
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: G1460440714
OpenAlex ID: W2965632969