Fano-Kondo Effect In Quantum Dot Coupled To Ferromagnetic Leads System Under The Coulomb Interaction

Quantum dot system is considered as typical representation of Mesoscopic quantum effect, especially after finding the phenomenon of very evident Fano-Kondo effect in tunneling conductance of quantum dot, which greatly increase people's interest in these fields. In the quantum dot system, mesoscopic Kondo effect leads to the increase of conductance, because Kondo resonance localized at the Fermi level provides the current with a new channel. However, density of states of quantum dot and transmission rate of systems change, due to the effect of Coulomb interaction between electronics. When the interaction reaches a certain level, they are mutated, which results in mutation of system's conductance.Recently, aimed at T-double-quantum dot system, using Scribe Bose and Bose mean-field approximation as average value( Vkασ=Vkασba , t ab=tab ba bb ,εm=εm+λm , ba ,bb ,λa andλb can be obtained by kinematics and non-equilibrium Green's function equation.), deriving the Hamiltonian operator with Coulomb interaction by Green's function, the relationship of quantum dots'occupation number and Coulomb interaction of T-double-quantum-dot system, the change of density of states and transmission rate with Coulomb interaction and variation of w are researched.The result shows that (1) under the influence of Coulomb interaction, the quantum dot in mutation temperature, electronic transport is impeded by system, mutation temperature varies with the coupling intensity, Kondor temperature is changed by the Coulomb interaction. ( 2 ) in the weak-coupling case, the Kondo resonance state of the two quantum dots does not form an effective molecular, which will be restrained by pseudo-potential; in strong-coupling case, the binding and the anti-binding states are formed, the coupling effect of two quantum dots becomes more obvious, man-made molecular is formed evidently, Kondo state of every quantum dot is increased by the interaction, energy levels corresponding to the binding and the anti-binding states naturally split, so that the Kondo resonance peak was split into two peaks near the Fermi level. The new results are helpful in exploring the electronic correlation in spintronics.