On Thermal Nieh-Yan Anomaly in Topological Weyl Materials
Abstract
We discuss the possibility of gravitational Nieh-Yan anomaly of the type ∂μj5μ=γ T2Ta∧Ta in topological Weyl materials, where T is temperature and Ta is the effective or emergent torsion. In contrast to the non-universal parameter A in the conventional (zero temperature) Nieh-Yan anomaly with canonical dimensions of momentum, the parameter γ is dimensionless. This suggests that the dimensionless parameter can be fundamental, being determined by the geometry, topology, and number of the number of chiral quantum fields without any explicit non-universal UV scales. This conforms with previous results in the literature, as well as spectral flow calculations using torsional magnetic field at finite temperature.
- Publication:
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Soviet Journal of Experimental and Theoretical Physics Letters
- Pub Date:
- February 2020
- DOI:
- 10.1134/S0021364019240020
- arXiv:
- arXiv:1911.03382
- Bibcode:
- 2020JETPL.110..789N
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Superconductivity;
- High Energy Physics - Theory
- E-Print:
- 4 pages, submitted to JETP Lett. arXiv admin note: substantial text overlap with arXiv:1909.08936