Large magnetothermopower effect in Dirac materials (Sr/Ca)MnBi2
Kefeng Wang, Limin Wang, C. Petrovic
TL;DR
This study reveals a large magnetothermopower effect in (Sr/Ca)MnBi$_2$ Dirac materials, with significant temperature and magnetic field dependence linked to shifts in chemical potential near Dirac points.
Contribution
It demonstrates the first large magnetothermopower effect in (Sr/Ca)MnBi$_2$ and links it to magnetic field-induced shifts in chemical potential near Dirac points.
Findings
Thermopower in SrMnBi$_2$ is positive and enhanced by magnetic field.
Thermopower in CaMnBi$_2$ is negative and suppressed by magnetic field.
Magnetic field significantly alters carrier density and thermopower in these materials.
Abstract
We report temperature and magnetic field dependence of the thermal transport properties in single crystals of (Sr/Ca)MnBi with linear energy dispersion. In SrMnBi thermopower is positive, indicating hole-type carriers and the magnetic field enhances the thermopower significantly. The maximum change of thermopower is about 1600% in 9 T field and at 10 K. A negative thermopower is observed in CaMnBi with dominant electron-type carriers and, in contrast, the magnetic field suppresses the absolute value of thermopower. First-principle band structure shows that the chemical potential is close to the Dirac-cone-like points in linear bands. The magnetic field suppresses the apparent Hall carrier density of CaMnBi below 50 K. The large magnetothermopower effect in (Sr/Ca)MnBi is attributed to the magnetic field shift of chemical potential
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.