Electron spin and charge switching in a coupled quantum dot quantum ring system

Abstract

Few-electron systems confined in a quantum dot laterally coupled to a surrounding quantum ring in the presence of an external magnetic field are studied by exact diagonalization. The distribution of electrons between the dot and the ring is influenced by the relative strength of the dot and ring confinement, the gate voltage and the magnetic field which induces transitions of electrons between the two parts of the system. These transitions are accompanied by changes in the periodicity of the Aharonov-Bohm oscillations of the ground-state angular momentum. The singlet-triplet splitting for a two electron system with one electron confined in the dot and the other in the ring exhibits piecewise linear dependence on the external field due to the Aharonov-Bohm effect for the ring-confined electron, in contrast to smooth oscillatory dependence of the exchange energy for laterally coupled dots in the side-by-side geometry.

to appear in PRB in August 2004

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Cited by in corpus (11)

• Few-electron eigenstates of concentric double quantum rings
• Wave function engineering in quantum dot-ring nanostructures
• Dot-ring nanostructure: Rigorous analysis of many-electron effects
• Near-threshold properties of the electronic density of layered quantum-dots
• Controlled exchange interaction for quantum logic operations with spin qubits in coupled quantum dots
• Electrical control of spin relaxation time in complex quantum nanostructures
• Resonance states in a cylindrical quantum dot with an external magnetic field
• Quantum Dot-Ring Nanostructure - a Comparison of Different Approaches
• Effective tuning of electron charge and spin distribution in a dot-ring nanostructure at the ZnO interface
• Quantum Hall droplet laterally coupled to a quantum ring
• Magnetic-field-induced binding of few-electron systems in shallow quantum dots