Fast nuclear spin relaxation rates in tilted cone Weyl semimetals: redshift factors from Korringa relation

Spin lattice relaxation rate is investigated for 3D tilted cone Weyl semimetals (TCWSMs). The nuclear spin relaxation rate is presented as a function of temperature and tilt parameter. We find that the relaxation rate behaves as (1 - zeta(2))(-alpha) with alpha approximate to 9 where 0 <= zeta < 1 is the tilt parameter. We demonstrate that such a strong enhancement for zeta less than or similar to 1 that gives rise to very fast relaxation rates, is contributed by a new hyperfine interactions arising from the tilt itself. This can be attributed to the combination of anisotropy of the Fermi surface and an additional part related to the structure of the spacetime: extracting an effective density of states (DOS) <(rho)over tilde> from the Korringa relation, we show that it is related to the DOS rho of the tilted cone dispersion by the 'redshift factor' as (rho) over tilde = rho/root 1 - zeta(2). We interpret this relation as NMR manifestation of an emergent underlying spacetime structure in TCWSMs.

Automated summary

The spin lattice relaxation rate in 3D tilted cone Weyl semimetals was investigated, showing a unique behavior influenced by the tilt parameter. The strong enhancement of relaxation rates for zeta less than or similar to 1 is attributed to new hyperfine interactions arising from the tilt itself. Extracting an effective density of states reveals a relation to the underlying spacetime structure, showcasing a manifestation in TCWSMs.