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arXiv · 1904.03179

Quantized Thermoelectric Hall Effect Induces Giant Power Factor in a Topological Semimetal

Fei Han·Nina Andrejevic·Thanh Nguyen·Vladyslav Kozii·Quynh Nguyen·Tom Hogan·Zhiwei Ding·Ricardo Pablo-Pedro·Shreya Parjan·Brian Skinner·Ahmet Alatas·Ercan Alp·Songxue Chi·Jaime Fernandez-Baca·Shengxi Huang·Liang Fu·Mingda Li
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Abstract

Thermoelectrics are promising by directly generating electricity from waste heat. However, (sub-)room-temperature thermoelectrics have been a long-standing challenge due to vanishing electronic entropy at low temperatures. Topological materials offer a new avenue for energy harvesting applications. Recent theories predicted that topological semimetals at the quantum limit can lead to a large, non-saturating thermopower and a quantized thermoelectric Hall conductivity approaching a universal value. Here, we experimentally demonstrate the non-saturating thermopower and quantized thermoelectric Hall effect in the topological Weyl semimetal (WSM) tantalum phosphide (TaP). An ultrahigh longitudinal thermopower Sxx= 1.1x10^3 muV/K and giant power factor ~525 muW/cm/K^2 are observed at ~40K, which is largely attributed to the quantized thermoelectric Hall effect. Our work highlights the unique quantized thermoelectric Hall effect realized in a WSM toward low-temperature energy harvesting applications.

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Fei Han, Nina Andrejevic, Thanh Nguyen, Vladyslav Kozii, Quynh Nguyen, Tom Hogan, Zhiwei Ding, Ricardo Pablo-Pedro, Shreya Parjan, Brian Skinner, Ahmet Alatas, Ercan Alp, Songxue Chi, Jaime Fernandez-Baca, Shengxi Huang, Liang Fu, Mingda Li. 2019-04-05. Quantized Thermoelectric Hall Effect Induces Giant Power Factor in a Topological Semimetal. https://doi.org/10.1038/s41467-020-19850-2

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