https://doi.org/10.1140/epjb/e20020086
Electronic properties of model quantum-dot structures in zero and finite magnetic fields
Laboratory of Physics, Helsinki University of Technology,
PO Box 1100, 02015 HUT, Finland
Corresponding author: a hri@hugo.hut.fi
Received:
16
October
2001
Revised:
17
January
2002
Published online: 15 March 2002
We have computed electronic structures and total energies of circularly confined two-dimensional quantum dots and their lateral dimers in zero and finite uniform external magnetic fields using different theoretical schemes: the spin-density-functional theory (SDFT), the current-and-spin-density-functional theory (CSDFT), and the variational quantum Monte Carlo (VMC) method. The SDFT and CSDFT calculations employ a recently-developed, symmetry-unrestricted real-space algorithm allowing solutions which break the spin symmetry. Results obtained for a six-electron dot in the weak confinement limit and in zero magnetic field as well as in a moderate confinement and in finite magnetic fields enable us to draw conclusions about the reliability of the more approximative SDFT and CSDFT schemes in comparison with the VMC method. The same is true for results obtained for the two-electron quantum dot dimer as a function of inter-dot distance. The structure and role of the symmetry-breaking solutions appearing in the SDFT and CSDFT calculations for the above systems are discussed.
PACS: 71. – Electronic structure of bulk materials / 73.21.-b – Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems / 85.35.Be – Quantum well devices (quantum dots, quantum wires, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002