Kondo effect and singlet-triplet splitting in coupled quantum dots in a magnetic field

Abstract

We study two tunnel-coupled quantum dots each with a spin 1/2 and attached to leads in the Coulomb blockade regime. We study the interplay between Kondo correlations and the singlet-triplet exchange splitting $K$ between the two spins. We calculate the cotunneling current with elastic and inelastic contributions and its renormalization due to Kondo correlations, away and at the degeneracy point K=0. We show that these Kondo correlations induce pronounced peaks in the conductance as function of magnetic field $B$, inter-dot coupling $t_0$, and temperature. Moreover, the long-range part of the Coulomb interaction becomes visibile due to Kondo correlations resulting in an additional peak in the conductance vs $t_0$ with a strong $B$-field dependence. These conductance peaks thus provide direct experimental access to $K$, and thus to a crucial control parameter for spin-based qubits and entanglement.

4 pages, 4 figures

References in corpus (8)

• Kondo effect in real quantum dots
• Two-stage Kondo effect in a quantum dot at high magnetic field
• Quantum Phase Transition in a Multi-Level Dot
• Kondo resonant spectra in coupled quantum dots
• Kondo effect induced by a magnetic field
• Spin-based quantum computation in multielectron quantum dots
• Mean Field Theory of the Kondo Effect in Quantum Dots with an Even Number of Electrons
• Multi-parameter scaling of the Kondo effect in quantum dots with an even number of electrons

Cited by in corpus (10)

• Tunable Non-local Spin Control in a Coupled Quantum Dot System
• Kondo effect in quantum dots
• Singlet-triplet decoherence due to nuclear spins in a double quantum dot
• Cotunneling Spectroscopy in Few-Electron Quantum Dots
• Transport through a double quantum dot in the sequential- and co- tunneling regimes
• Two-stage Kondo effect in a four-electron artificial atom
• The connection between noise and quantum correlations in a double quantum dot
• Transconductance of a double quantum dot system in the Kondo regime
• Kondo effect in nanostructures
• Magnetically-Tuned Kondo Effect in a Molecular Double Quantum Dot: Role of the Anisotropic Exchange