Quantum phase transitions in the systems of parallel quantum dots

Abstract

We study the low-temperature transport properties of the systems of parallel quantum dots described by the N-impurity Anderson model. We calculate the quasiparticle scattering phase shifts, spectral functions and correlations as a function of the gate voltage for N up to 5. For any N, the conductance at the particle-hole symmetric point is unitary. For N >= 2, a transition from ferromagnetic to antiferromagnetic impurity spin correlations occurs at some gate voltage. For N >= 3, there is an additional transition due to an abrupt change in average impurity occupancy. For odd N, the conductance is discontinuous through both quantum phase transitions, while for even N only the magnetic transition affects the conductance. Similar effects should be experimentally observable in the systems of quantum dots with ferromagnetic conduction-band-mediated inter-dot exchange interactions.

5 pages, 4 figures

References in corpus (4)

• Magnetic field dependent transmission phase of a double dot system in a quantum ring
• Transport spectroscopy of Kondo quantum dots coupled by RKKY interaction
• Spin-charge separation and simultaneous spin and charge Kondo effect
• Indirect Exchange Interaction between two Quantum Dots in an Aharonov-Bohm Ring

Cited by in corpus (4)

• Properties of anisotropic magnetic impurities on surfaces
• Splitting of the Kondo resonance in anisotropic magnetic impurities on surfaces
• Numerical renormalization group study of two-channel three-impurity triangular clusters
• Finite-temperature conductance signatures of quantum criticality in double quantum dots