Large, nonsaturating thermopower in a quantizing magnetic field

The thermoelectric effect is the generation of an electrical voltage from a temperature gradient in a solid material due to the diffusion of free charge carriers from hot to cold. Identifying materials with a large thermoelectric response is crucial for the development of novel electric generators and coolers. We theoretically consider the thermopower of Dirac/Weyl semimetals subjected to a quantizing magnetic field. We contrast their thermoelectric properties with those of traditional heavily doped semiconductors and show that, under a sufficiently large magnetic field, the thermopower of Dirac/Weyl semimetals grows linearly with the field without saturation and can reach extremely high values. Our results suggest an immediate pathway for achieving record-high thermopower and thermoelectric figure of merit, and they compare well with a recent experiment on Pb1–xSnxSe.United States. Department of Energy. Office of Basic Energy Science (award no. DE-SC0001088)United States. Department of Energy. Office of Basic Energy Science (award no. DE-SC0001299/DE-FG02-09ER46577 (thermoelectricity))United States. Department of Energy. Division of Materials Sciences and Engineering (award no. DE-SC0010526 (topological materials)