Nernst and seebeck effects inα-T3lattice

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Physics

Background:

• The α-T3 lattice is a tunable system interpolating between graphene and the dice lattice.
• Understanding thermoelectric transport phenomena like Seebeck and Nernst effects is crucial for energy applications.
• Previous studies have explored these effects in graphene and dice lattices separately.

Purpose of the Study:

• To investigate the Seebeck and Nernst effects in the α-T3 lattice as a function of the parameter α.
• To analyze the influence of magnetic fields on these thermoelectric coefficients.
• To explore the role of lattice boundaries (zigzag and armchair) on the observed effects.

Main Methods:

• Utilized the tight-binding Hamiltonian method to model the electronic band structure.
• Employed non-equilibrium Green's function (NEGF) methods for calculating transport coefficients.
• Investigated systems with and without applied magnetic fields.

Main Results:

• For α=0 (graphene), Seebeck and Nernst coefficients match known graphene behavior, with flat bands present.
• Non-zero α introduces an odd Seebeck coefficient dependence on Fermi energy, creating a large peak in the band gap for zigzag boundaries.
• Magnetic fields enhance the Seebeck coefficient peak with increasing α. The Nernst coefficient's zeroth peak height increases with α, eventually splitting, with distinct behaviors for zigzag and armchair boundaries.

Conclusions:

• The α-T3 lattice offers tunable thermoelectric properties through the parameter α.
• Boundary effects significantly impact the Seebeck and Nernst coefficients, particularly in the band gap region.
• The observed phenomena highlight the potential of α-T3 lattices for advanced thermoelectric devices.