Electron and hole spin dynamics in semiconductor quantum dots

Gündoğdu, Kenan; Hall, K. C.; Koerperick, Edwin J.; Pryor, Craig; Flatté, Michael E.; Boggess, Thomas F.; Shchekin, O.B.; Deppe, D.G.

doi:10.1063/1.1857067

Cited by 37 publications

(50 citation statements)

References 29 publications

(30 reference statements)

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“…This is in contrast to other techniques that have been used for studying spin relaxation in QDs, for example, time-resolved Faraday rotation [19][20][21] and time-resolved photoluminescence with circularly polarized light [22][23][24][25]. In both techniques, spin orientation is optically created by circularly polarized photoexcitation of suitably oriented QDs and its subsequent relaxation is manifested as the decay of the signal.…”

Section: Introductionmentioning

confidence: 93%

Spin relaxation in zinc blende and wurtzite CdSe quantum dots

Huxter

Kim

et al. 2010

Chemical Physics Letters

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Section: Introductionmentioning

confidence: 93%

Spin relaxation in zinc blende and wurtzite CdSe quantum dots

Huxter

Kim

et al. 2010

Chemical Physics Letters

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“…We compute the electron ground state using straindependent eight-band k · p theory in the envelope approximation with finite differences on a real-space grid [38][39][40]. The strain is calculated using linear elasticity continuum theory.…”

Section: Theory Of Spin-correlated Orbital Moments In Anisotropicmentioning

confidence: 99%

Anisotropy of electron and holegtensors of quantum dots: An intuitive picture based on spin-correlated orbital currents

et al. 2016

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Koenraad, P. M. (2016). Anisotropy of electron and hole g tensors of quantum dots: An intuitive picture based on spin-correlated orbital currents. Physical Review B, 93(3), [035311]. DOI: 10.1103/PhysRevB.93.035311 General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Using single spins in semiconductor quantum dots as qubits requires full control over the spin state. As the g tensor provides the coupling in a Hamiltonian between a spin and an external magnetic field, a deeper understanding of the g tensor underlies magnetic-field control of the spin. The g tensor is affected by the presence of spin-correlated orbital currents, of which the spatial structure has been recently clarified. Here we extend that framework to investigate the influence of the shape of quantum dots on the anisotropy of the electron g tensor. We find that the spin-correlated orbital currents form a simple current loop perpendicular to the magnetic moment's orientation. The current loop is therefore directly sensitive to the shape of the nanostructure: for cylindrical quantum dots, the electron g-tensor anisotropy is mainly governed by the aspect ratio of the dots. Through a systematic experimental study of the size dependence of the separate electron and hole g tensors of InAs/InP quantum dots, we have validated this picture. Moreover, we find that through size engineering it is possible to independently change the sign of the in-plane and growth direction electron g factors. The hole g tensor is found to be strongly anisotropic and very sensitive to the radius and elongation. The comparable importance of itinerant and localized currents to the hole g tensor complicates the analysis relative to the electron g tensor.

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“…Therefore, the hole spins do not precess and sh is enhanced up to several orders of magnitude. [13][14][15] The fact that the first minimum reaches nearly zero signal indicates that equal amounts of electron and hole spins are present in the system with comparable decay times. Apart from the coherent peak, the full time response can be well described by the following fitting function:…”

Section: Resultsmentioning

confidence: 99%

Optical control over electron g factor and spin decoherence in (In,Ga)As∕GaAs quantum dots

Rietjens

Quax

Bosco

et al. 2008

Journal of Applied Physics

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We have studied the dependence of the electron in-plane g factor and spin decoherence time on the built-in electric field (Ei) at the position of a single layer of self-assembled (In,Ga)As∕GaAs quantum dots (QDs). Control of Ei is achieved by inducing screening charges in a p-i-n GaAs matrix with a continuous wave (cw) laser. Using a time-resolved pump-probe technique to measure the spin dynamics via the magneto-optical Kerr effect, we observe a large hole spin decoherence time of 440ps. Measurements as function of the cw laser power and, thus, of Ei show that the electron spin decay time in the QDs depends strongly on Ei and decreases from 310to110ps with increasing Ei. We attribute this effect to increasing tunneling rates of electrons out of the QDs at high Ei. We observe a slight increase of the electron g factor from 0.40±0.03 to 0.46±0.04 with increasing Ei, which might be a result of a changing wavefunction as a result of a different confinement potential due to Ei.

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Electron and hole spin dynamics in semiconductor quantum dots

Cited by 37 publications

References 29 publications

Spin relaxation in zinc blende and wurtzite CdSe quantum dots

Spin relaxation in zinc blende and wurtzite CdSe quantum dots

Anisotropy of electron and holegtensors of quantum dots: An intuitive picture based on spin-correlated orbital currents

Optical control over electron g factor and spin decoherence in (In,Ga)As∕GaAs quantum dots

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