Few-electron artificial molecules formed by laterally coupled quantum rings
arXiv:0810.0178 · doi:10.1103/PhysRevB.78.245306
Abstract
We study the artificial molecular states formed in laterally coupled double semiconductor nanorings by systems containing one, two and three electrons. An interplay of the interring tunneling and the electron-electron interaction is described and its consequences for the magnetization and charging properties of the system are determined. It is shown that both the magnetic dipole moment generated by the double ring structure and the chemical potential of the system as function of the external magnetic field strongly depend on the number of electrons and the interring barrier thickness. Both the magnetization and chemical potentials exhibit cusps at the magnetic fields inducing ground-state parity and / or spin transformations. The symmetry transformations are discussed for various tunnel coupling strengths: from rings coupled only electrostatically to the limit of coalesced rings. We find that in the ground-states for rings of different radii the magnetic field transfers the electron charge from one ring to the other. The calculations are performed with the configuration interaction method based on an approach of Gaussian functions centered on a rectangular array of points covering the studied structure. Electron-electron correlation is also discussed.
References in corpus (26)
- Coupled quantum dots as quantum gates
- Spectroscopy of nanoscopic semiconductor rings
- Energy spectra of quantum rings
- Hilbert space structure of a solid state quantum computer: two-electron states of a double quantum dot artificial molecule
- Quantum rings for beginners: Energy spectra and persistent currents
- Optical transitions in quantum ring complexes
- Polarized excitons in nanorings and the `optical' Aharonov-Bohm effect
- Coulombically Interacting Electrons in a One-dimensional Quantum Dot
- Two-electron quantum dot molecule: Composite particles and the spin phase diagram
- Few-electron eigenstates of concentric double quantum rings
- Electro-magnetic Aharonov-Bohm effect in a 2-D electron gas ring
- Networks of quantum nanorings: programmable spintronic devices
- Spatial ordering of charge and spin in quasi one-dimensional Wigner molecules
- Persistent and radiation-induced currents in distorted quantum rings
- Roto-vibrational spectrum and Wigner crystallization in two-electron parabolic quantum dots
- Electronic structure of few-electron concentric double quantum rings
- Three-electron anisotropic quantum dots in variable magnetic fields: exact results for excitation spectra, spin structures, and entanglement
- Magnetoconductance properties of rectangular arrays of spintronic quantum rings
- Competing mechanisms for singlet-triplet transition in artificial molecules
- Quantum-dot lithium in strong-interaction regime: Depolarization of electron spins by magnetic field
- Artificial molecular quantum rings: Spin density functional theory calculations
- Optical response of two-dimensional few-electron concentric double quantum rings: A local-spin-density-functional theory study
- Non-circular semiconductor nanorings of type I and II: Emission kinetics in the exciton Aharonov-Bohm effect
- Electron-acoustic-phonon scattering and electron relaxation in two-coupled quantum rings
- Characteristic molecular properties of one-electron double quantum rings under magnetic fields
- Size effects in the exchange coupling between two electrons in quantum wire quantum dots
Cited by in corpus (11)
- Implications of Simultaneous Requirements for Low Noise Exchange Gates in Double Quantum Dots
- Quantum rings with time dependent spin-orbit coupling: Rabi oscillations, spintronic Schrodinger-cat states, and conductance properties
- Artificial quantum-dot Helium molecules: Electronic spectra, spin structures, and Heisenberg clusters
- Two-dimensional quantum rings with oscillating spin-orbit interaction strength: A wave function picture
- Pinning of electron densities in quantum rings by defects: symmetry constraints and distribution of persistent currents
- Singlet-triplet avoided crossings and effective factor versus spatial orientation of spin-orbit-coupled quantum dots
- Tuning the exchange interaction by electric field in laterally coupled quantum dots
- Coupling of bonding and antibonding electron orbitals in double quantum dots by spin-orbit interaction
- Artificial molecular quantum rings under magnetic field influence
- Effect of Coulomb correlation on electron transport through concentric quantum ring-quantum dot structure
- Evaluation of Gaussian integrals for the modeling of two-dimensional quantum systems