Fingerprints of the conformal anomaly in the thermoelectric transport in Dirac and Weyl semimetals

The conformal anomaly, a quantum anomaly related to metric deformations in conformally invariant systems, has been recently shown to give rise to a special contribution to the Nernst signal, which remains finite at zero temperature and chemical potential. In this work we provide a Kubo calculation that confirms the result of this unexpected signal in the conformal limit and extends the calculation to finite temperature and chemical potential. As a result, we predict a distinctive experimental signature of the conformal anomaly in the form of a plateau behavior in the thermoelectric coefficient as a function of the chemical potential in the extreme quantum limit.