Giant anomalous Nernst signal in the antiferromagnet YbMnBi2

Abstract

Searching for a high anomalous Nernst effect (ANE) is crucial for thermoelectric energy conversion applications because the associated unique transverse geometry facilitates module fabrication. Topological ferromagnets with large Berry curvatures show high ANEs; however, they face drawbacks such as strong magnetic disturbances and low mobility due to high magnetization. Herein, we demonstrate that YbMnBi2, a canted antiferromagnet, has a large ANE conductivity of ~10 Am-1K-1 that surpasses the common high values (i.e. 3-5 Am-1K-1) observed so far in ferromagnets. The canted spin structure of Mn guarantees a nonzero Berry curvature but generates only a weak magnetization three orders of magnitude lower than that of general ferromagnets. The heavy Bi with a large spin-orbit coupling enables a high ANE and low thermal conductivity, whereas its highly dispersive px/y orbitals ensure low resistivity. The high anomalous transverse thermoelectric performance and extremely small magnetization makes YbMnBi2 an excellent candidate for transverse thermoelectrics.

References in corpus (6)

• Berry phase effect in anomalous thermoelectric transport
• Spectral and Fermi surface properties from Wannier interpolation
• Mott Relation for Anomalous Hall and Nernst effects in Ga1-xMnxAs Ferromagnetic Semiconductors
• Transverse thermoelectric generation using magnetic materials
• Observation of anomalous Ettingshausen effect and large transverse thermoelectric conductivity in permanent magnets
• Design strong anomalous Hall effect via spin canting in antiferromagnetic nodal line materials

Cited by in corpus (2)

• Observation of the anomalous Nernst effect in altermagnetic candidate Mn5Si3
• The discovery of three-dimensional Van Hove singularity