Magic numbers and persistent current oscillations in electron–hole quantum dots

2016 ◽  
Vol 30 (03) ◽  
pp. 1650013 ◽  
Author(s):  
Aleksandr A. Vasilchenko ◽  
Demid M. Tolkachev
Keyword(s):  
Magnetic Field ◽  
Quantum Dots ◽  
Angular Momentum ◽  
Total Angular Momentum ◽  
Charge Carriers ◽  
Persistent Current ◽  
Magic Numbers ◽  
Two Dimensional ◽  
Electron Hole ◽  
Current Oscillations

The system of Kohn–Sham equations is solved self-consistently for the two-dimensional, spatially separated electrons and holes. We find the series of magic numbers for the total angular momentum of the electrons and holes in a strong magnetic field. The change of the angular momentum of the charge carriers is shown to lead to the persistent current oscillations.

scholarly journals Oscillatory persistent currents in quantum rings

2021 ◽  
Author(s):  
Alexander A. Vasilchenko
Keyword(s):  
Angular Momentum ◽  
Density Functional ◽  
Total Angular Momentum ◽  
Persistent Current ◽  
Magic Numbers ◽  
Persistent Currents ◽  
Empirical Expression ◽  
Functional Theory ◽  
Quantum Rings ◽  
The Density Functional Theory

Abstract The density functional theory is used to study persistent currents in two-dimensional quantum rings containing several electrons. We find a series of magic numbers for the total angular momentum of electrons in the strong magnetic field and show that changes in the angular momentum of electrons lead to persistent current oscillations. We suggest an empirical expression for the period of persistent current in quantum rings and examine the effect of Coulomb interaction on the properties of persistent currents.

FOUR-ELECTRON SYSTEMS CONFINED IN MULTILAYER QUANTUM DOTS

2007 ◽  
Vol 21 (21) ◽  
pp. 1399-1413 ◽  
Author(s):  
WENFANG XIE
Keyword(s):  
Quantum Dots ◽  
Angular Momentum ◽  
Ground State ◽  
Electronic Structures ◽  
Electron Interaction ◽  
Magic Numbers ◽  
Electron Systems ◽  
Diagonalization Method ◽  
Exact Diagonalization Method ◽  
Ground State Electron

In this paper, we studied four-electron systems confined in one-, two-, and four-layer quantum dots, by the exact diagonalization method. A vertical magnetic field to the confinement plane is considered. The ground-state electronic structures and the spin and angular momentum transitions for different magnetic fields are investigated. Series of magic numbers of angular momentum which minimize the ground-state electron–electron interaction energy have been discovered. These are connected to the exchange and rotational symmetries of the systems.

Photocurrent in a hybrid system of 1-thioglycerol and HgTe quantum dots

2003 ◽  
Vol 789 ◽  
Author(s):  
Hyunsuk Kim ◽  
Kyoungah Cho ◽  
Byungdon Min ◽  
Jong Soo Lee ◽  
Man Young Sung ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Hybrid System ◽  
Wavelength Dependence ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Free Carriers ◽  
Transmission Electron ◽  
Colloidal Method ◽  
First Time

ABSTRACTPhotocurrent mechanism in a hybrid system of 1-thioglycerol and HgTe quantum dots(QDs) was studied for the first time in the intra-red (IR) range. 1-thioglycerol-capped HgTe QDs were prepared using colloidal method in aqueous solution; the synthesis and size of the HgTe QDs were examined by x-ray diffraction, Raman scattering, and high-resolution transmission electron microscopy. Absorption and photoluminescence spectra of the capped HgTe QDs revealed the strong excitonic peaks in the range from 900 to 1100nm, because of their widened band gap due to the shrinkage of their sizes to about 3 nm. The wavelength dependence of the photocurrent for the hybred system of the 1-thioglycerol and HgTe QDs was very close to that of the absorption spectrum, indicating that charge carriers photoexcited in the HgTe QDs give direct contribution to the photocurrent in the medium of 1-thioglycerol. In this hybrid system, the photo-excited electrons in the HgTe QDs are strongly confined, but the photo-excited holes act as free carriers. Hence, in the photocurrent mechanism of the this hybrid system, only holes among electron-hole pairs created by incident photons in the HgTe QDs are transferred to 1-thioglycerol surrounding HgTe QDs and contribute photocurrent flowing in the medium of 1-thioglycerol.

FEW-ELECTRON DOUBLE-LAYER QUANTUM DOTS IN MAGNETIC FIELDS: ENERGY SPECTRUM OF AN ARTIFICIAL MOLECULE

1999 ◽  
Vol 13 (09n10) ◽  
pp. 291-302
Author(s):  
WENFANG XIE ◽  
CHUANYU CHEN ◽  
D. L. LIN
Keyword(s):  
Magnetic Field ◽  
Angular Momentum ◽  
Magnetic Fields ◽  
Double Layer ◽  
Ground State ◽  
Energy Spectra ◽  
Electron Interaction ◽  
Magic Numbers ◽  
Total Orbital Angular Momentum ◽  
Artificial Molecule

An exact method is proposed to diagonalize the Hamiltonian of a double-layer quantum dot containing N electrons in arbitrary magnetic fields. For N = 3 and 4, energy spectra of the dot are calculated as a function of the applied magnetic field. As a result of the electron–electron interaction, complete sets of "magic numbers" are found to characterize the total orbital angular momentum of the N-electron dot in the ground state for both the polarized and unpolarized spins. It is shown that discrete transitions of the ground state between magic numbers takes place when the external magnetic field changes. The origin of the magic numbers is completely explained in terms of the underlying symmetry.

scholarly journals Магнитная циркулярная поляризация фотолюминесценции экситонов

2018 ◽  
Vol 60 (8) ◽  
pp. 1503
Author(s):  
Е.Л. Ивченко
Keyword(s):  
Magnetic Field ◽  
Quantum Dots ◽  
Quantum Wells ◽  
Circular Polarization ◽  
Spectral Lines ◽  
Theoretical Studies ◽  
Two Dimensional ◽  
Bulk Semiconductors ◽  
Polarization Of Luminescence ◽  
Composition Fluctuations

AbstractExperimental and theoretical studies of circular polarization of photoluminescence of excitons (MCPL) in semiconductors placed in an external magnetic field are reviewed. The advantage of the MCPL method is its relative simplicity. In particular, it does not require spectral resolution of the Zeeman sublevels of an exciton and may be applied to a wide class of objects having broad photoluminescence spectral lines or bands: in bulk semiconductors with excitons localized on the defects of the crystal lattice and composition fluctuations, in structures with quantum wells and quantum dots of types I and II, in two-dimensional transition metals dichalcogenides and quantum microcavities. The basic mechanisms of the magnetic circular polarization of luminescence are considered. It is shown that either known mechanisms should be modified or additional mechanisms of the MCPL should be developed to describe the polarized photoluminescence in newly invented nanosystems.

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