Strain-engineered self-assembled semiconductor quantum dot lattices

Lee, H.; Johnson, J. A.; He, M. Y.; Speck, J. S.; Petroff, P. M.

doi:10.1063/1.1336554

Cited by 135 publications

(73 citation statements)

References 29 publications

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“…Quantum-dot lattices for electrons [6][7][8] and optical lattices for atoms [9][10][11][12] have provided a new experimental setup where the lattice structure can be formed artificially and, consequently, structures which do not exist in nature can also be experimentally studied and utilized. Moreover, in optical lattices, atom dynamics can be studied without problems caused by lattice defects or phonons [9,13,14] and the atoms trapped in the lattice can be chosen to be fermions or bosons.…”

Section: Introductionmentioning

confidence: 99%

Many-particle dynamics of bosons and fermions in quasi-one-dimensional flat-band lattices

2013

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The difference between boson and fermion dynamics in quasi-one-dimensional lattices is studied by calculating the persistent current in small quantum rings and by exact simulations of the timeevolution of the many-particle state in two cases: Expansion of a localized cloud, and collisions in a Newtons cradle. We consider three different lattices which in the tight binding model exhibit flat bands. The physical realization is considered to be an optical lattice with bosonic or fermionic atoms. The atoms are assumed to interact with a repulsive short range interaction. The different statistics of bosons and fermions lead to different dynamics. Spinless fermions are easily trapped in the flat-band states due to the Pauli exclusion principle, which prevents them from interacting, while bosons are able to push each other out from the flat-band states.

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Section: Introductionmentioning

confidence: 99%

Many-particle dynamics of bosons and fermions in quasi-one-dimensional flat-band lattices

2013

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“…An array of InGaAs self-assembled quantum dots is an excellent candidate for a scalable QC architecture because recent advances in the fabrication technology have substantially improved the control of size and location of the nanostructures. [18][19][20][21][22][23][24] The electron Zeeman energies of InGaAs self-assembled quantum dots can fluctuate due to inhomogeneous hyperfine energies induced by the electron-nuclear spin interaction. This fluctuation of the hyperfine energies can be quite large since all the nuclei in an InGaAs quantum dot and its environment GaAs buffer have nonzero magnetic moment and the resulting number N of nuclei interacting with the electron spin is in the range 10 4 -10 6 .…”

Section: Introductionmentioning

confidence: 99%

Effect of electron-nuclear spin interactions for electron-spin qubits localized in InGaAs self-assembled quantum dots

Lee

Allmen

Oyafuso

et al. 2005

Journal of Applied Physics

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Lee, Seungwon; von Allmen, Paul; Oyafuso, Fabiano; and Klimeck, Gerhard, "Effect of electron-nuclear spin interactions for electronspin qubits localized in InGaAs self-assembled quantum dots" (2005 The effect of electron-nuclear spin interactions on qubit operations is investigated for a qubit represented by the spin of an electron localized in an InGaAs self-assembled quantum dot. The localized electron wave function is evaluated within the atomistic tight-binding model. The electron Zeeman splitting induced by the electron-nuclear spin interaction is estimated in the presence of an inhomogeneous environment characterized by a random nuclear spin configuration, by the dot-size distribution, alloy disorder, and interface disorder. Due to these inhomogeneities, the electron Zeeman splitting varies from one qubit to another by the order of 10 −6 , 10 −6 , 10 −7 , and 10 −9 eV, respectively. Such fluctuations cause errors in exchange operations due to the inequality of the Zeeman splitting between two qubits. However, the error can be made lower than the quantum error threshold if an exchange energy larger than 10 −4 eV is used for the operation. This result shows that the electron-nuclear spin interaction does not hinder quantum-dot based quantum computer architectures from being scalable even in the presence of inhomogeneous environments.

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“…On the other hand, the formation of nanosized structures in which QDs are laterally coupled provides a challenge in epitaxial crystal growth. High quality QDs in well-defined arrangements, such as QD arrays [3][4][5] and ordered QD groups, [6][7][8][9] have been realized by self-organized strain engineering. The number of QDs within a single group or QD cluster, formed by using strained-layer superlattice ͑SL͒ templates, 7,8 is controlled by varying the growth temperature of the SL template and the thickness of the GaAs separation layer between the SL template and the QD layer.…”

Section: Coherent Acoustic Phonons In Strain Engineeredmentioning

confidence: 99%

Coherent acoustic phonons in strain engineered InAs∕GaAs quantum dot clusters

Bogaart

Lippen

Haverkort

et al. 2006

Applied Physics Letters

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Coherent excitation of the quasilongitudinal and quasitransverse acoustic phonon mode in strain engineered InAs∕GaAs quantum dot (QD) clusters grown on (311)B GaAs is monitored by means of time-resolved differential reflection spectroscopy. Carrier capture within the ordered QD clusters initiate coherent acoustic phonon excitation, which induces a transient modulation of the local strain-induced piezoelectric field within the QD clusters. The excited acoustic phonons then modulate the optical properties of the QDs through the quantum-confined Stark effect, causing distinct oscillations of the differential reflection signal.

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Strain-engineered self-assembled semiconductor quantum dot lattices

Cited by 135 publications

References 29 publications

Many-particle dynamics of bosons and fermions in quasi-one-dimensional flat-band lattices

Many-particle dynamics of bosons and fermions in quasi-one-dimensional flat-band lattices

Effect of electron-nuclear spin interactions for electron-spin qubits localized in InGaAs self-assembled quantum dots

Coherent acoustic phonons in strain engineered InAs∕GaAs quantum dot clusters

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