Paramagnetic shift in thermally annealed CdxZn1−xSe quantum dots

Margapoti, E.; Alves, Fabrizio M.; Mahapatra, S.; López‐Richard, V.; Worschech, L.; Βrunner, Karl; Qu, Fanyao; Destefani, C. F.; Menéndez-Proupín, E.; Bougerol, Catherine; Forchel, A.; Marques, G. E.

doi:10.1088/1367-2630/14/4/043038

Cited by 12 publications

(7 citation statements)

References 14 publications

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“…In turn, the magnetic field driven occupancy of the symmetric and antisymmetric conduction band states leads to an out-of-phase oscillations of the S and AS emissions between integer filling factors. This confirms that the modulation of structural parameters in nanostructures affects the coupling between heavy-and light-hole subbands [20][21][22] that, in turn, influences the DCP variation with magnetic field. Thus, we demonstrate that the valence band states play an important role in the circular polarization of the PL emissions in GaAs/AlGaAs strongly coupled DQW structures.…”

Section: Discussionsupporting

confidence: 70%

Quantum oscillations of spin polarization in a GaAs/AlGaAs double quantum well

et al. 2012

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We employ the circular polarization-resolved magneto-photoluminescence technique to probe the spin character of electron and hole states in a GaAs/AlGaAs strongly coupled double quantum well system. The photoluminescence intensities of the lines associated with symmetric and antisymmetric electron states present clear out-of-phase oscillations between integer values of the filling factor ν and are caused by magnetic field induced changes in the population of occupied Landau levels near to the Fermi level of the system. Moreover, the degree of circular polarization of these emissions also exhibits the oscillatory behavior with increasing magnetic field. Both quantum oscillations observed in the PL intensities and in the degree of polarizations may be understood in terms of a simple single-particle approach model. The k · p method was used to calculate the photoluminescence peak energies and the degree of circular polarizations in the double quantum well structure as a function of the magnetic field. These calculations prove that the character of valence band states plays an important role in the determination of the degree of circular polarization and, thus, resulting in a magnetic field induced change of the polarization sign.

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Section: Discussionsupporting

confidence: 70%

Quantum oscillations of spin polarization in a GaAs/AlGaAs double quantum well

et al. 2012

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“…This effect has already been predicted and measured for confined excitons. 27,28 For a qualitative discussion, let us assume the magnetic energy of a trapped electron as given by an effective Hamiltonian and presented in Eq. (17).…”

Section: Resultsmentioning

confidence: 99%

“…This coupling modulates various effective parameters such as effective masses, Lande factors, and diamagnetic shifts, as well as their dependence on external fields. 27,28 …”

Section: Electronic Structurementioning

confidence: 99%

Strain and localization effects in InGaAs(N) quantum wells: Tuning the magnetic response

Lopes-Oliveira

Herval

Gordo

et al. 2014

Journal of Applied Physics

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Articles you may be interested inEffects of a nearby Mn delta layer on the optical properties of an InGaAs/GaAs quantum well Energy dependence of electron effective mass and effect of wave function confinement in a nanoscale In0.53Ga0.47As/In0.52Al0.48As quantum wellWe investigated effects of localization and strain on the optical and magneto-optical properties of diluted nitrogen III-V quantum wells theoretically and experimentally. High-resolution x-ray diffraction, photoluminescence (PL), and magneto-PL measurements under high magnetic fields up to 15 T were performed at low temperatures. Bir-Pikus Hamiltonian formalism was used to study the influence of strain, confinement, and localization effects. The circularly polarized magneto-PL was interpreted considering localization aspects in the valence band ground state. An anomalous behavior of the electron-hole pair magnetic shift was observed at low magnetic fields, ascribed to the increase in the exciton reduced mass due to the negative effective mass of the valence band ground state. V C 2014 AIP Publishing LLC. [http://dx.

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“…Whereas the composition of the electron ground state is predominately the product of an s-like envelope function and an s-like Bloch function, the dominant composition of the hole ground state is the product of an s-like envelope function and a plike Bloch function. The greater Bloch function angular momentum leads to complex orbital momentum struc-ture of the hole state wave functions and sensitive dependences of hole state ordering on size and strain [42,43].…”

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confidence: 99%

Spin-Orbit-Induced Circulating Currents in a Semiconductor Nanostructure

et al. 2014

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Circulating orbital currents produced by the spin-orbit interaction for a single electron spin in a quantum dot are explicitly evaluated at zero magnetic field, along with their effect on the total magnetic moment (spin and orbital) of the electron spin. The currents are dominated by coherent superpositions of the conduction and valence envelope functions of the electronic state, are smoothly varying within the quantum dot, and are peaked roughly halfway between the dot center and edge. Thus the spatial structure of the spin contribution to the magnetic moment (which is peaked at the dot center) differs greatly from the spatial structure of the orbital contribution. Even when the spin and orbital magnetic moments cancel (for g = 0) the spin can interact strongly with local magnetic fields, e.g. from other spins, which has implications for spin lifetimes and spin manipulation.

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Paramagnetic shift in thermally annealed Cd_xZn_1−xSe quantum dots

Cited by 12 publications

References 14 publications

Quantum oscillations of spin polarization in a GaAs/AlGaAs double quantum well

Quantum oscillations of spin polarization in a GaAs/AlGaAs double quantum well

Strain and localization effects in InGaAs(N) quantum wells: Tuning the magnetic response

Spin-Orbit-Induced Circulating Currents in a Semiconductor Nanostructure

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