Colossal Nernst power factor in topological semimetal NbSb${}_2$

Abstract

Today solid-state cooling technologies below liquid nitrogen boiling temperature (77 K), crucial to quantum information technology and probing quantum state of matter, are greatly limited due to the lack of good thermoelectric and/or thermomagnetic materials. Here, we report the discovery of colossal Nernst power factor of 3800$\times$10${}^{-4}$ W m${}^{-1}$ K${}^{-2}$ under 5 T at 25 K and high Nernst figure-of-merit of 71$\times$10${}^{-4}$ K${}^{-1}$ under 5 T at 20 K in topological semimetal NbSb${}_2$ single crystals. The observed high thermomagnetic performance is attributed to large Nernst thermopower and longitudinal electrical conductivity, and relatively low transverse thermal conductivity. The large and unsaturated Nernst thermopower is the result of the combination of highly desirable electronic structures of NbSb${}_2$ having compensated high mobility electrons and holes near Fermi level and strong phonon-drag effect. This discovery opens an avenue for exploring material option for the solid-state heat pumping below liquid nitrogen temperature.

References in corpus (5)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Titanic Magnetoresistance in WTe2
• Anisotropic giant magnetoresistance in NbSb2
• Large Nernst effect and field enhanced transversal ZT in ZrTe5
• Thermopower and thermal conductivity in the Weyl semimetal NbP

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