Nature Communications
Observation of a thermoelectric Hall plateau in the extreme quantum limit
Nature Communications · 11, 1046 (2020)
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Introduction
In a strong field, carriers in ZrTe₅ can be confined to the lowest Landau level. The team combined thermoelectric and electrical measurements to obtain the transverse thermoelectric conductivity, αxy. At a fixed temperature it leveled off with increasing field, in agreement with a model for three-dimensional Dirac electrons in the extreme quantum limit.
A closer reading
The plateau concerns heat carried transverse to an electric field. Keeping αxy distinct from thermopower and ordinary Hall conductivity helps in reading the plots. The authors also check an engineering consequence: magnetoresistance offsets the rise in thermopower, so the power factor gains little. A striking transport signature and an improved energy-conversion device require different evidence.