Artificial molecular quantum rings under magnetic field influence

Abstract

Size effect on the conduction band orbital character of anatase TiO2 nanocrystals Appl. Phys. Lett. 99, 183101 (2011) Doping-based control of the energetic structure of photovoltaic co-deposited films APL: Org. Electron. Photonics 4, 205 (2011) Doping-based control of the energetic structure of photovoltaic co-deposited films Appl. Phys. Lett. 99, 133301 (2011) Band structure engineering and vacancy induced metallicity at the GaAs-AlAs interface Appl. Phys. Lett. 99, 123501 (2011) Communication: Uncovering molecule-TiO2 interactions with nonlinear spectroscopy J. Chem. Phys. 135, 081101 (2011) Additional information on J. Appl. Phys. The ground states of a few electrons confined in two vertically coupled quantum rings in the presence of an external magnetic field are studied systematically within the current spin-density functional theory. Electron-electron interactions combined with inter-ring tunneling affect the electronic structure and the persistent current. For small values of the external magnetic field, we recover the zero magnetic field molecular quantum ring ground state configurations. Increasing the magnetic field many angular momentum, spin, and isospin transitions are predicted to occur in the ground state. We show that these transitions follow certain rules, which are governed by the parity of the number of electrons, the single-particle picture, Hund's rules, and many-body effects.

Linear and nonlinear optical absorption coefficients in GaAs/Ga1−xAlxAs concentric double quantum rings: Effects of hydrostatic pressure and aluminum concentration

“…Since the first quantum rings (QRs) of nanoscopic sizes were fabricated [8,9], these fascinating systems have drawn a considerable attention due to the interest in studying physical phenomena such as the Aharonov-Bohm effect [10][11][12][13] and the appearance of persistent currents [14]. Theoretical studies on vertically [15][16][17][18] and laterally [19,20] coupled double QRs have discussed the molecular properties of these systems. QRs may also be coupled concentrically.…”

Ground state and infrared response of triple concentric quantum ring structures

“…It displays oscillations due to changes in the TCQR ground state induced by the applied magnetic field. 13,14,43,44 The behavior is slightly more regular for B Ն 2.5 T since there are no polarization changes within that range. However, current jumps due to both changes in the electron occupation of the constituent rings and changes of the occupied sp angular momenta within each ring are present in all the studied range of magnetic fields.…”

“…Vertically coupled nanoscopic rings are formed by rings with similar radii and thus do not display this effect. 13,14 …”

“…8 As quantum dots, quantum rings can be coupled forming "artificial ring molecules." 9,10 Theoretical studies on double quantum rings coupled vertically [11][12][13][14] and laterally 15,16 have discussed the molecular properties of these systems.…”

Tuning of few-electron states and optical absorption anisotropy in GaAs quantum rings

“…[23][24][25][26][27] The interplay between the RSOI and DSOI results in a periodic potential in an isolated QR that breaks the rotational symmetry, produces gaps in the energy spectrum and suppresses the persistent currents. [28][29][30][31] However, in these studies, one-electron models with effective mass approximation were used, without taking into account FIG. 1: (Color online) Schematic diagram of a considered multielectron QR in (001)-oriented GaAs/AlGaAs quantum well.…”