Abstract
We first analyze the recent experimental data on the nuclear spin-lattice relaxation rate of the Weyl semimetal TaP. We argue that its nonmonotonic temperature dependence is explained by the temperature-dependent chemical potential of Weyl fermions. We also develop the theory of the Knight shift in Weyl semimetals, which contains two counteracting terms. The diamagnetic term follows with , and being the high-energy cutoff, chemical potential, and temperature, respectively, and is always negative. The paramagnetic term scales with and changes sign depending on the doping level. Altogether, the Knight shift is predicted to vanish or even change sign upon changing the doping or the temperature, making it a sensitive tool to identify Weyl points. We also calculate the Korringa relation for Weyl semimetals which shows an unusual energy dependence rather than being constant as expected for a noninteracting Fermi system.
- Received 29 June 2018
DOI:https://doi.org/10.1103/PhysRevB.99.115107
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