Kondo screening of a high-spin Nagaoka state in a triangular quantum dot

Abstract

We study transport through a triangle triple quantum dot connected to two noninteracting leads using the numerical renormalization group (NRG). The triangle has a high-spin ground state of S=1 caused by a Nagaoka ferromagnetism, when it is isolated and has one extra electron introduced into a half-filling. The results show that the conduction electrons screen the local moment via two separate stages with different energy scales. The half of the S=1 is screened first by one of the channel degrees, and then at very low temperature the remaining half is fully screened to form a Kondo singlet. The transport is determined by two phase shifts for quasi-particles with even and odd parities, and then a two-terminal conductance in the series configuration is suppressed $g_{\mathrm{series}}\simeq 0$, while plateau of a four-terminal parallel conductance reaches a Unitary limit value $g_{\mathrm{parallel}}\simeq 4e^2/h$ of two conducting modes.

2pages, 2figures: fig1 is revised to show a narrow dip found in the series conductance

References in corpus (4)

• Magnetically Tunable Kondo - Aharonov-Bohm Effect in a Triangular Quantum Dot
• Numerical renormalization group approach to a quartet quantum-dot array connected to reservoirs:gate-voltage dependence of the conductance
• Determination of the phase shifts for interacting electrons connected to reservoirs
• NRG approach to the transport through a finite Hubbard chain connected to reservoirs

Cited by in corpus (14)

• Nagaoka ferromagnetism observed in a quantum dot plaquette
• Tunable superconducting coupling of quantum dots via Andreev bound states in semiconductor-superconductor nanowires
• Numerical renormalization group study of two-channel three-impurity triangular clusters
• Kondo effects in a triangular triple quantum dot: NRG study in the whole region of the electron filling
• Kondo effects in a triangular triple quantum dot with lower symmetries
• Ab Initio Exact Diagonalization Simulation of the Nagaoka Transition in Quantum Dots
• The influence of Coulomb correlations on nonequilibrium quantum transport in quadruple quantum-dot structure
• Emergent Electric Polarization by Kondo Effect in a Triangular Triple Quantum Dot
• Full Counting Statistics of Spin-Flip/Conserving Charge Transitions in Pauli-Spin Blockade
• Ground-state properties of a triangular triple quantum dot connected to superconducting leads
• SU(2)-SU(4) Kondo Crossover and Emergent Electric Polarization in a Triangular Triple Quantum Dot
• Gate-voltage dependence of Kondo effect in a triangular quantum dot
• Antisymmetric Spin-Orbit Coupling Effect on Kondo-Induced Electric Polarization in a Triangular Triple Quantum Dot
• Spin-polarized transport in quadruple quantum dots attached to ferromagnetic leads