Nernst effect in anisotropic four-terminal topological nodal-line semimetals.
J Phys Condens Matter
; 35(37)2023 Jun 19.
Article
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| ID: mdl-37295441
ABSTRACT
The Nernst effect is the transverse mode of thermoelectric transport, in which a longitudinal thermal gradient induces a transverse current in the conductor while under a perpendicular magnetic field. Here the Nernst effect in a mesoscopic topological nodal-line semimetals (TNLSMs) system of four-terminal cross-bar with the spin-orbit coupling under a perpendicular magnetic field is studied. The Nernst coefficientNcin two non-equivalen connection modes (kz-ymode andkx-ymode) is calculated based on the tight-binding Hamiltonian combined with the nonequilibrium Green's function method. When the magnetic field is absent withφ = 0.0, the Nernst coefficientNc=0is exactly regardless of the temperature. When the magnetic field is not zero, the Nernst coefficient exhibits a series of densely oscillating peaks. The height of peak strongly depends on the magnetic field, and the Nernst coefficient is an even function of the Fermi energyEFsatisfying the symmetrical propertyNc(-EF)=Nc(EF). The Nernst coefficient is also closely related to the temperatureT. When the temperature is very low (orTâ0), the Nernst coefficient depends linearly on temperature. In the presence of a strong magnetic field, the Nernst coefficient shows peaks when the Fermi energy crosses the Landau levels. Under the weak magnetic field, the influence of spin-orbit coupling in TNLSMs materials on Nernst effect is very obvious. In the presence of the mass term, thePT-symmetry of the system is destroyed, the nodal ring of TNLSMs is broken and an energy gap will be opened. The Nernst coefficientNchas a large value in the energy gap, which is very promising for the application of the transverse thermoelectric transport.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
J Phys Condens Matter
Asunto de la revista:
BIOFISICA
Año:
2023
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Article