Fate of the spin-1/2 Kondo effect in the presence of temperature gradients

摘要: We consider a strongly interacting quantum dot connected to two leads held at quite different temperatures. Our aim is study the behavior of Kondo effect in presence large thermal biases. use three approaches, namely, perturbation formalism based on Hamiltonian, slave-boson mean-field theory for Anderson model charging energies, and truncated equation-of-motion approach beyond Hartree-Fock approximation. The former formalisms yield suppression peak gradients above temperature, showing remarkably good agreement despite their ranges validity. third technique allows us analyze full density states within wide range energies. Additionally, we have investigated transport properties (electric current thermocurrent) linear response. In voltage-driven case, reproduce split differential conductance due electrochemical potentials. temperature-driven observe nonlinear thermocurrent as function applied gradient. Depending parameters, can find nontrivial zeros electric finite values temperature bias. Importantly, these direct access system's characteristic energy scales (Kondo energy).