Influence of quantum dot shape on the Landé<i>g</i>-factor determination

Prado, Silvio José; Trallero‐Giner, C.; Alcalde, A. M.; López‐Richard, V.; Marques, G. E.

doi:10.1103/physrevb.69.201310

Cited by 58 publications

(41 citation statements)

References 18 publications

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“…Moreover, similarly to bulk semiconductors and quantum wells, 52,54-56 the magnetic field induced mixing of heavy and light hole states and quantum confinement strongly renormalizes heavy-hole g-factor in quantum dots from its value in the bulk. [57][58][59][60][61][62][63] Indeed, in the presence of the magnetic field the wavevector k in Eq. (4) is replaced by k + eA(r)/c , where A(r) = (1/2)B × r is the vector potential of the magnetic field.…”

Section: Longitudinal G-factor G H1mentioning

confidence: 99%

Magnetic field induced valence band mixing in [111] grown semiconductor quantum dots

Durnev¹,

Glazov²,

Ivchenko³

et al. 2013

Phys. Rev. B

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We present a microscopic theory of the magnetic field induced mixing of heavy-hole states ±3/2 in GaAs droplet dots grown on (111)A substrates. The proposed theoretical model takes into account the striking dot shape with trigonal symmetry revealed in atomic force microscopy. Our calculations of the hole states are carried out within the Luttinger Hamiltonian formalism, supplemented with allowance for the triangularity of the confining potential. They are in quantitative agreement with the experimentally observed polarization selection rules, emission line intensities and energy splittings in both longitudinal and transverse magnetic fields for neutral and charged excitons in all measured single dots.

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Section: Longitudinal G-factor G H1mentioning

confidence: 99%

Magnetic field induced valence band mixing in [111] grown semiconductor quantum dots

Durnev¹,

Glazov²,

Ivchenko³

et al. 2013

Phys. Rev. B

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“…With decreasing structure size, the issues of finite size and shape effects become non-negligible [4,5] including issues of stability against decay and structural rearrangement [6][7][8]. Small structures are also increasing sensitive to external perturbations, such as the stress caused by the substrate interface [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Nano-scale equilibrium crystal shapes

Degawa¹,

Szalma²,

Williams³

2005

Surface Science

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The finite size and interface effects on equilibrium crystal shape (ECS) have been investigated for the case of a surface free energy density including step stiffness and inverse-square step-step interactions. Explicitly including the curvature of a crystallite leads to an extra boundary condition in the solution of the crystal shape, yielding a family of crystal shapes, governed by a shape parameter c. The total crystallite free energy, including interface energy, is minimized for c=0, yielding in all cases the traditional PT shape (z~x 3/2 ). Solutions of the crystal shape for c≠0 are presented and discussed in the context of meta-stable states due to the energy barrier for nucleation. Explicit scaled relationships for the ECS and meta-stable states in terms of the measurable step parameters and the interfacial energy are presented.

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“…In particular, electrical control of the effective Landé g-factor in semiconductor nanostructures has been a major focus of recent research, with theoretical investigations predicting strong g * tunability in both magnitude and sign [5][6][7]. The ability to invert the sign of the g-factor and tune the system through a state of zero spin polarisation (g * = 0) could be a valuable asset in engineering solid-state spin devices [8][9][10].…”

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confidence: 99%

Electrical control of the sign of thegfactor in a GaAs hole quantum point contact

et al. 2016

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Zeeman splitting of 1D hole subbands is investigated in quantum point contacts (QPCs) fabricated on a (311) oriented GaAs-AlGaAs heterostructure. Transport measurements can determine the magnitude of the g-factor, but cannot usually determine the sign. Here we use a combination of tilted fields and a unique off-diagonal element in the hole g-tensor to directly detect the sign of g * . We are able to tune not only the magnitude, but also the sign of the g-factor by electrical means, which is of interest for spintronics applications. Furthermore, we show theoretically that the resulting behaviour of g * can be explained by the momentum dependence of the spin-orbit interaction.Electrical manipulation of spin is the underlying principal of many proposed spintronic and quantum computing device architectures [1][2][3][4]. In particular, electrical control of the effective Landé g-factor in semiconductor nanostructures has been a major focus of recent research, with theoretical investigations predicting strong g * tunability in both magnitude and sign [5][6][7]. The ability to invert the sign of the g-factor and tune the system through a state of zero spin polarisation (g * = 0) could be a valuable asset in engineering solid-state spin devices [8][9][10].In this regard, quantum confined hole systems in GaAs are prime candidates due to the strong coupling between spin and orbital motion in the valence band [11]. The spin 3/2 nature of valence band holes in GaAs leads to several unique properties such as a tensor structure of g * with large anisotropy between all three spatial directions [12,13], and tunability of the g-factor across orders of magnitude [14][15][16].Previous studies of the g-factor of quantum confined holes revealed a non-monotonic dependance of |g * | on the gate bias, suggestive of a change in sign of g * [6,17]. However, these studies could not directly detect the sign of g * , only its magnitude. In this work, we utilise a novel approach to directly detect the sign of g * by exploiting a unique property of the (311) GaAs hole g-tensor, and demonstrate a gate-controlled sign change of g * in a hole quantum point contact (QPC) on (311) GaAs.We also introduce a theoretical model showing that the observed sign reversal of g * arises from the in-plane momentum dependence of the spin-orbit interaction in the valence band. Typically it is not possible to experimentally probe the directional k-dependence of the 2D hole g-tensor, since transport measurements represent an average over all k-states at the Fermi surface. However, by using an electrostatically controlled QPC fabricated along particular in-plane directions of a 2D hole system, * Alex.Hamilton@unsw.edu.au we can perform a direct spectroscopic measurement of g * , and investigate its dependence on the magnitude and direction of the in-plane momentum [14,17,18].The device used in this work was fabricated from a (311)A-oriented heterostructure, in which a 2D hole system is induced at an AlGaAs/GaAs interface by applying a negative voltage (-0.7V) to a...

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Influence of quantum dot shape on the Landég-factor determination

Cited by 58 publications

References 18 publications

Magnetic field induced valence band mixing in [111] grown semiconductor quantum dots

Magnetic field induced valence band mixing in [111] grown semiconductor quantum dots

Nano-scale equilibrium crystal shapes

Electrical control of the sign of thegfactor in a GaAs hole quantum point contact

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