Kondo effect in coupled quantum dots under magnetic fields

Abstract

The Kondo effect in coupled quantum dots is investigated theoretically under magnetic fields. We show that the magnetoconductance (MC) illustrates peak structures of the Kondo resonant spectra. When the dot-dot tunneling coupling $V_C$ is smaller than the dot-lead coupling $\Delta$ (level broadening), the Kondo resonant levels appear at the Fermi level ($E_F$). The Zeeman splitting of the levels weakens the Kondo effect, which results in a negative MC. When $V_C$ is larger than $\Delta$, the Kondo resonances form bonding and anti-bonding levels, located below and above $E_F$, respectively. We observe a positive MC since the Zeeman splitting increases the overlap between the levels at $E_F$. In the presence of the antiferromagnetic spin coupling between the dots, the sign of MC can change as a function of the gate voltage.

6 pages, 3 figures

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Cited by in corpus (11)

• Multi-impurity Anderson model for quantum dots coupled in parallel
• RKKY and magnetic field interactions in coupled Kondo quantum dots
• Kondo effect and anti-ferromagnetic correlation in transport through tunneling-coupled double quantum dots
• Non-equilibrium Kondo effect in asymmetrically coupled quantum dot
• Numerical sub-gap spectroscopy of double quantum dots coupled to superconductors
• Spectral Density of the Two-Impurity Anderson Model
• A thermally driven out-of-equilibrium two-impurity Kondo system
• Nonequilibrium Steady States and Fano-Kondo Resonances in an AB Ring with a Quantum Dot
• Swapping entangled Kondo resonances in parallel-coupled double quantum dots
• Gate-tunable split Kondo effect in a carbon nanotube quantum dot
• Kondo effect in a double quantum-dot molecule under the effect of an electric and magnetic field