Optical initialization of hole spins in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi></mml:math>-doped quantum dots: Orientation efficiency and loss of coherence

Gawełczyk, Michał; Machnikowski, Paweł

doi:10.1103/physrevb.87.195315

Cited by 6 publications

(4 citation statements)

References 38 publications

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“…However, the usage of doped structures comes with a number of drawbacks, first of which is the lowering of the material quality (especially optical) caused by the doping as well as problems with proper doping (particularly p-type) of some materials, such as InGaAs [18]. Moreover, it has been shown that there is an intrinsic spin dephasing present in the initialization of resident spins caused both by the temporal excitation to charged excitonic complex states with subsequent recombination itself and by the phonon reservoir reaction to this carrier system evolution, which takes place during the laser pulse [28]. This may be important in future applications but affects also the results of current experiments [29], in particular those based on the resonant spin amplification effect [20,30,31], where the spin coherence is crucial for the formation of the observed signal.…”

Section: Introductionmentioning

confidence: 99%

Spin dynamics and magneto-optical response in charge-neutral tunnel-coupled quantum dots

Gawełczyk¹,

Machnikowski²

2017

Semicond. Sci. Technol.

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We model the electron and hole spin dynamics in an undoped double quantum dot structure, considering the carrier tunneling between quantum dots. Taking into account also the presence of an in-plane or tilted magnetic field, we provide the simulation of magneto-optical experiments, like the time resolved Kerr rotation measurement, which are performed currently on such structures to probe the temporal spin dynamics. With our model, we reproduce the experimentally observed effect of the extension of the spin polarization life time caused by the spatial charge separation, which may occur in structures of this type. Moreover, we provide a number of qualitative predictions concerning the necessary conditions for observation of this effect as well as about possible channels of its suppression, including the spin-orbit coupling, which leads to tunneling of carriers accompanied by a spin-flip. We consider also the impact of the magnetic field tilting, which results in an interesting spin polarization dynamics.

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Section: Introductionmentioning

confidence: 99%

Spin dynamics and magneto-optical response in charge-neutral tunnel-coupled quantum dots

Gawełczyk¹,

Machnikowski²

2017

Semicond. Sci. Technol.

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“…For very large pumping powers, the hole SDT extracted from the data (not shown) decreases slightly, indicating sample heating. A detailed theoretical study of rapid hole spin dephasing, induced by phonons, was performed recently [28].…”

Section: Initialization Of a Hole Spin Polarizationmentioning

confidence: 99%

Hole spin dynamics and valence‐band spin excitations in two‐dimensional hole systems

Korn

Schüller

2013

Physica Status Solidi (b)

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This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.In recent years, the spin dynamics and spin-orbit interaction in GaAs-based two-dimensional hole systems (2DHS) have created a lot of attention. This is due to the complex structure of the valence band, with its p-like character, which leads to strong spin-orbit coupling. In this paper, we review our recent studies on hole spin dynamics and valence-band spin excitations in GaAs-based, p-modulation-doped quantum wells (QWs). In 2DHS with low carrier concentration, we demonstrate that maximizing the heavy-hole-light-hole band splitting by changing the QW width leads to long hole spin dephasing times at low temperatures. Different mechanisms for initializing a resident hole spin polarization by optical excitation are presented. To accurately determine hole spin dynamics parameters, the resonant spin amplification technique is utilized. The strong anisotropy of the hole g factor, and electrical g factor control are investigated, using this technique. In highly doped 2DHS, we use resonant inelastic light scattering (RILS) to study the spin splitting of the valence band. We observe a low-energy spin-density excitation (SDE), which is a measure of the spin splitting of the hole ground state. By varying the laser energy in the RILS experiment, we can resonantly probe the k dependence of the spin splitting. The spectral shape of the SDE depends on the orientation of the light polarizations relative to the crystal axes and reflects the in-plane anisotropy of the valence-band spin splitting.

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“…Dynamics of a carrier spin in semiconductor quantum dots (QDs), as well as other semiconductor nanostructures, is a subject of active studies, both theoretical and experimental, due to potential implementations in fields of spintronics and quantum information processing 1,2 . High-fidelity initialization 3,4 , control 5,6 , readout and storage 7 of the information encoded in the spin are essential for future applications. These can be achieved with hole spin due to its relatively long coherence time 8 , which is related to significantly weaker hyperfine interaction as compared to the electron case [9][10][11] .…”

Section: Introductionmentioning

confidence: 99%

Hole spin-flip transitions in a self-assembled quantum dot

Krzykowski,

Gawarecki,

Machnikowski

2020

Preprint

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In this work, we investigate hole spin-flip transitions in a single self-assembled InGaAs/GaAs quantum dot. We find the hole wave functions using the 8-band k • p model and calculate phononassisted spin relaxation rates for the ground-state Zeeman doublet. We systematically study the importance of various admixture-and direct spin-phonon mechanisms giving rise to the transition rates. We show that the biaxial and shear strain constitute dominant spin-admixture coupling mechanisms. Then, we demonstrate that hole spin lifetime can be increased if a quantum dot is covered by a strain-reducing layer. Finally, we show that the spin relaxation can be described by an effective model.

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Optical initialization of hole spins inp-doped quantum dots: Orientation efficiency and loss of coherence

Cited by 6 publications

References 38 publications

Spin dynamics and magneto-optical response in charge-neutral tunnel-coupled quantum dots

Spin dynamics and magneto-optical response in charge-neutral tunnel-coupled quantum dots

Hole spin dynamics and valence‐band spin excitations in two‐dimensional hole systems

Hole spin-flip transitions in a self-assembled quantum dot

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