Manipulating the spin polarization of excitons in a single quantum dot by optical means

Larsson, L. A.; Moskalenko, E. S.; Holtz, Per-Olof

doi:10.1063/1.3554422

Cited by 5 publications

(4 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast to those studies performed under large external magnetic fields, experimental reports under zero magnetic field have so far been insufficient [25][26][27][28][29] . As shown later, excitation by a circularly polarized beam induces a considerable Overhauser field under a wide range of experimental conditions, even if one does not intend to induce an Overhauser field.…”

Section: Introductionmentioning

confidence: 82%

Dynamic nuclear spin polarization in self-assembled quantum dots under zero magnetic field

Matsusaki,

Kaji,

Yamamoto

et al. 2017

Preprint

View full text Add to dashboard Cite

We studied the zero-field dynamic nuclear spin polarization in a single In0.75Al0.25As/Al0.3Ga0.7As quantum dot. Even without any external magnetic field, the positive trion excited by the circularlypolarized light generated an Overhauser field of up to ∼0.8 T. From the excitation power dependences of the Overhauser field and degree of circular polarization of the photoluminescence spectra, the relation between the Overhauser field and Knight field under zero external magnetic field was revealed clearly. In addition, we found that the nuclear depolarization rate decreased as the magnitude of the longitudinal magnetic field increased, which seemed to be caused by the influence of the quadrupolar interaction of nuclear spins. Further, the key parameters describing the dynamics of a coupled electron-nuclear spin system, the electron g-factor and the fluctuation of the Overhauser field, were evaluated in a typical single InAlAs quantum dot.

show abstract

Section: Introductionmentioning

confidence: 82%

Dynamic nuclear spin polarization in self-assembled quantum dots under zero magnetic field

Matsusaki,

Kaji,

Yamamoto

et al. 2017

Preprint

View full text Add to dashboard Cite

show abstract

“…Ingenious and numerous experimental studies have shown the influence of reduction of dimensionality on band structure then on the emission-absorption energies as well as on excitonic transport mechanisms in quantum wells heterostructures [11]. Others determined the intersubband transitions within semiconductor quantum dots (QDs) [12,13] if not manipulating the excitonic spin states [14,15]. In this, context, a new class of nanoparticles recently appeared, the core/shell quantum dots (CSQDs) such as ZnS/ZnO or CdSe/ZnTe.…”

Section: Introductionmentioning

confidence: 99%

External electric field effect and impact of encapsulating matrix on optical and electronic properties within CdSe/ZnSe core/shell QDs

Jbeli¹,

Yahyaoui²,

Zeiri³

et al. 2021

Phys. Scr.

View full text Add to dashboard Cite

In this study, we have carried out a theoretical investigation of CdSe/ZnSe core/shell spherical quantum dot (CSQD) embedded in different dielectric matrix. The effect of surrounding matrix and the external electric field on the linear and third-order nonlinear real and imaginary parts of the dielectric function have been simulated numerically using the effective mass approximation and taking into account the compact density matrix approach. The electronic band structure and corresponding wave functions were calculated by solving the Schrödinger equation in the framework evoked previously. The study revealed a significant blue shift of the transition energies under electric field offering the possibility of adjusting them. In addition, by varying the dielectric matrices enveloping our main structure, it was also found that the choice of the pattern of the matrix is fundamental for the manipulation of the resonance peak energies of the dielectric function. RECEIVED

show abstract

“…In principle, no circularly polarized emission should be observed when no external magnetic field is applied. However, it was recently shown that this restriction can be relaxed and PL from X 0 can become partially circularly polarized [24,25] when an effective magnetic field (i.e. Overhauser field) is created via dynamic polarization of nuclear spins of lattice atoms within QDs under cw excitation by circularly polarized light.…”

Section: Origin Of the Qd Pl And Pl Polarizationmentioning

confidence: 99%

Effects of a longitudinal magnetic field on spin injection and detection in InAs/GaAs quantum dot structures

Beyer¹,

Wang²,

Buyanova³

et al. 2012

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Abstract. Effects of a longitudinal magnetic field on optical spin injection and detection in InAs/GaAs quantum dot (QD) structures are investigated by optical orientation spectroscopy. An increase in optical and spin polarization of the QDs is observed with increasing magnetic field in the range of 0-2 T, and is attributed to suppression of exciton spin depolarization within the QDs that is promoted by hyperfine interaction and anisotropic electron-hole exchange interaction. This leads to a corresponding enhancement in spin detection efficiency of the QDs by a factor of up to 2.5. At higher magnetic fields when these spin depolarization processes are quenched, electron spin polarization in anisotropic QD structures (such as double QDs that are preferably aligned along a specific crystallographic axis) still exhibits rather strong field dependence under non-resonant excitation. In contrast, such field dependence is practically absent in more "isotropic" QD structures (e.g. single QDs). We attribute the observed effect to stronger electron spin relaxation in the spin injectors (i.e. wetting layer and GaAs barriers) of the lower-symmetry QD structures, which also explains the lower spin injection efficiency observed in these structures.PACS numbers: 73.21. La, 78.67.Hc, 72.25.Fe, 72.25.Rb IntroductionSemiconductor quantum dot (QD) structures are currently under intense investigations in view of their potential applications in spin-based quantum information technology and nanospintronics, as the three-dimensional carrier confinement in these structures promises suppression of many spin relaxation mechanisms that are predominant in semiconductors of higher dimensionality [1]. In threeand two-dimensional structures, the most important spin relaxation mechanisms such as the D'yakonov-Perel and Elliott-Yafet mechanisms are promoted by the motion of carriers. For confined carriers in QDs, the lack of carrier motion efficiently deactivates these spin relaxation mechanisms. Furthermore, their atomic-like, discrete energy level structure restricts efficiency of phonon-induced inelastic scattering processes. Hyperfine interactions of confined carriers with nuclear spins of host lattice atoms within QDs [2,3] and carrier-carrier exchange interaction [4] become the dominant spin relaxation mechanisms at low temperatures. The expected extended carrier spin lifetimes have been confirmed experimentally [5][6][7][8], and efficient room-temperature spin detection has also recently been demonstrated [9], which is encouraging for proposals of QDs in applications of quantum computing

show abstract

Manipulating the spin polarization of excitons in a single quantum dot by optical means

Cited by 5 publications

References 20 publications

Dynamic nuclear spin polarization in self-assembled quantum dots under zero magnetic field

Dynamic nuclear spin polarization in self-assembled quantum dots under zero magnetic field

External electric field effect and impact of encapsulating matrix on optical and electronic properties within CdSe/ZnSe core/shell QDs

Effects of a longitudinal magnetic field on spin injection and detection in InAs/GaAs quantum dot structures

Contact Info

Product

Resources

About