Spin polarization of carriers in resonant tunneling devices containing InAs self-assembled quantum dots

Nóbrega, J.A.; Gordo, V. Orsi; Galeti, H. V. A.; Gobato, Y. Galvão; Brasil, M. J. S. P.; Taylor, David; Орлита, М.; Henini, M.

doi:10.1016/j.spmi.2015.10.018

Cited by 5 publications

(2 citation statements)

References 25 publications

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“…However, all charge carriers inside these QDs are quantum-confined from all three spatial directions. Therefore, we tend to attribute this higher exponent value (~2) to the symptomatic presence of trions or biexcitons related to radiative recombination in QDs [37]. Such evidence of the presence of trions or biexcitons may also point towards the likelihood of non-radiative AR of these excitonic complexes [34], and how it is broadening the EL peaks in figure 3(b) at higher bias currents.…”

Section: Bias Dependence Of Electroluminescence From Qd and Qw-wlmentioning

confidence: 93%

Role of interface potential barrier, Auger recombination and temporal coherence in In_0.5Ga_0.5As/GaAs quantum dot-based p-i-n light emitting diodes

Singh¹,

Bhunia²,

Huwayz³

et al. 2018

J. Phys. D: Appl. Phys.

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In this work, we investigate the mechanisms that control the electroluminescence from p-i-n heterostructures containing self-assembled In0.5Ga0.5As quantum dots embedded inside GaAs/Al0.3Ga0.7As quantum well as a function of temperature and applied bias. Our results reveal that the carrier dynamics at the interface between the quantum dot and the quantum well plays a crucial role in the electroluminescence emission. At low temperatures, two distinct emission bands are observed. Initially at low bias current, we observe broad emissions from quantum well and wetting layers. Another dominant and sharp emission at lower energy arises from the quantum dots but only at higher bias currents. We discuss how a potential barrier between quantum dots and quantum well can control the density of injected carriers undergoing optical recombination. We have also investigated the role of carrier capture and escape, quantum-confined stark effect, and band filling effects in the electroluminescence emission. In addition, we demonstrate how measurements of temporal coherence of individual spectral peaks, can detect the presence of Auger recombination in quantum dots under high injection currents. Interestingly, a significant increase in temporal coherence of quantum dot emissions is observed, which could be due to a decrease in Auger recombination with increasing temperature.

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Section: Bias Dependence Of Electroluminescence From Qd and Qw-wlmentioning

confidence: 93%

Role of interface potential barrier, Auger recombination and temporal coherence in In_0.5Ga_0.5As/GaAs quantum dot-based p-i-n light emitting diodes

Singh¹,

Bhunia²,

Huwayz³

et al. 2018

J. Phys. D: Appl. Phys.

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“…Regarding the phonon emission in QDs, it has been mainly studied by considering the one phonon process because the relaxation rates for higher order processes are a few orders of magnitude smaller than the one phonon process at lattice temper ature close to the quantum operation temperature (T = 1 K) [4]. The spin-flip time T1 has been studied for single QD geometries and it has been shown that the external magnetic field and the lattice temperature are parameters of special importance in order to control the T1 [10][11][12][13][14][15][16][17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Spin qubits: spin relaxation in coupled quantum dots

Stavrou

2018

J. Phys.: Condens. Matter

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The spin-flip scattering mechanism in coupled self-assembled quantum dots made with InAs/GaAs with the use of realistic material parameters is theoretically and numerically investigated. The electron wave functions within the coupled system have been calculated by the 8-band strain dependent k • p theory. The phonon coupling to electrons is described by deformation potential and piezoelectric acoustic phonons. First order perturbation theory has been employed to evaluate the spin relaxation rates and spin-flip time T1. The numerical results show that parameters like the interdot distance and the applied static magnetic field are of crucial importance in spin-flip mechanism. The spin relaxation time has been also studied by varying the lattice temperature and by showing the differences between the quantum computing operation temperature (T ∼ 1 K) and large temperatures.

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Spin Polarization of Carriers in InGaAs Self-Assembled Quantum Rings Inserted in GaAs-AlGaAs Resonant Tunneling Devices

Gordo

Gobato

Galeti

et al. 2017

Journal of Elec Materi

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In this work, we have investigated transport and polarization resolved photoluminescence (PL) of n-type GaAs-AlGaAs resonant tunneling diodes (RTDs) containing a layer of InGaAs self-assembled quantum rings (QRs) in the quantum well (QW). All measurements were performed under applied voltage, magnetic fields up to 15 T and using linearly polarized laser excitation. It was observed that the QRs' PL intensity and the circular polarization degree (CPD) oscillate periodically with applied voltage under high magnetic fields at 2 K. Our results demonstrate an effective voltage control of the optical and spin properties of InGaAs QRs inserted into RTDs.

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Spin polarization of carriers in resonant tunneling devices containing InAs self-assembled quantum dots

Cited by 5 publications

References 25 publications

Role of interface potential barrier, Auger recombination and temporal coherence in In_0.5Ga_0.5As/GaAs quantum dot-based p-i-n light emitting diodes

Role of interface potential barrier, Auger recombination and temporal coherence in In_0.5Ga_0.5As/GaAs quantum dot-based p-i-n light emitting diodes

Spin qubits: spin relaxation in coupled quantum dots

Spin Polarization of Carriers in InGaAs Self-Assembled Quantum Rings Inserted in GaAs-AlGaAs Resonant Tunneling Devices

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Spin polarization of carriers in resonant tunneling devices containing InAs self-assembled quantum dots

Cited by 5 publications

References 25 publications

Role of interface potential barrier, Auger recombination and temporal coherence in In0.5Ga0.5As/GaAs quantum dot-based p-i-n light emitting diodes

Role of interface potential barrier, Auger recombination and temporal coherence in In0.5Ga0.5As/GaAs quantum dot-based p-i-n light emitting diodes

Spin qubits: spin relaxation in coupled quantum dots

Spin Polarization of Carriers in InGaAs Self-Assembled Quantum Rings Inserted in GaAs-AlGaAs Resonant Tunneling Devices

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Product

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Role of interface potential barrier, Auger recombination and temporal coherence in In_0.5Ga_0.5As/GaAs quantum dot-based p-i-n light emitting diodes

Role of interface potential barrier, Auger recombination and temporal coherence in In_0.5Ga_0.5As/GaAs quantum dot-based p-i-n light emitting diodes