Thermoelectric Effects in Carbon Nanotube Quantum Dot in the Kondo Regime

摘要

Thermoelectric effects in a carbon nanotube quantum dot in the Kondo regime are studied by the equation of motion method. The thermopower is highly sensitive to the structure of the spectral density near the Fermi edge. For temperatures close to the Kondo temperature the thermopower approaches a local minimum, which becomes sharper for orbital energies closer to the Fermi level. For higher temperatures the tjermopower increases, but in the temperature range corresponding to charging energy it again drops and achieves significant negative values. We examine the consequences of symmetry breaking of spin-orbital SU(4) system on thermopower.