Spin-preserving ultrafast carrier capture and relaxation in InGaAs quantum dots

Trumm, S.; Wesseli, M.; Krenner, Hubert J.; Schuh, Dieter; Bichler, Max; Finley, Jonathan J.; Betz, M.

doi:10.1063/1.2103399

Cited by 27 publications

(21 citation statements)

References 24 publications

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“…Carrier capture processes occur frequently in several semiconductor structures, e.g., scattering of carriers from the wetting layer to quantum dots [1][2][3][4][5][6], from a quantum wire to the embedded quantum dot [7][8][9], or from monolayers of transition metal dichalcogenides (TMDCs) to discrete states created by strain effects [10,11]. All those processes happen on subpicosecond time scales and on nanometric length scales and therefore are of genuinely quantum mechanical nature.…”

Section: Introductionmentioning

confidence: 99%

Spatio-Temporal Dynamics of Carrier Capture Processes: Simulation of Optical Signals

et al. 2017

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We perform simulations of time-resolved optical experiments of carrier-capture processes in a quantum wiredot system. Scattering of charge carriers with optical phonons of the quantum wire can result in transitions from the continuum states of the quantum wire to discrete states of the quantum dot. We treat the scattering of carriers with optical phonons within a Lindblad single-particle approach. By considering the coupling of carriers to a light field we are able to simulate pump-probe experiments which are shown to be capable of measuring the captured populations. We further discuss the influence of the Coulomb interaction on the obtained spectra.

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Section: Introductionmentioning

confidence: 99%

Spatio-Temporal Dynamics of Carrier Capture Processes: Simulation of Optical Signals

et al. 2017

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“…In Section 2, we directly analyze the transfer of photoinjected carriers from the WL to fully quantized QD levels [23]. The experiment relies on the transient bleaching of the WL band edge and the QD interband transitions in a two-color femtosecond transmission experiment.…”

Section: Introductionmentioning

confidence: 99%

Nonequilibrium carrier dynamics in self‐assembled InGaAs quantum dots

Wesseli

Ruppert

Trumm

et al. 2006

Physica Status Solidi (b)

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PACS 78. 47.+p, 78.67.Hc Carrier dynamics in InGaAs/GaAs quantum dots is analyzed with highly sensitive femtosecond transmission spectroscopy. In a first step, measurements on a large ensemble of nanoislands reveal the dynamical electronic filling of quantum dots from the surrounding wetting layer. Most interestingly, we find a spinpreserving phonon mediated scattering into fully localized states within a few picoseconds. Then, individual artificial atoms are isolated with metallic shadow masks. For the first time, a single self-assembled quantum dot is addressed in an ultrafast transmission experiment. We find bleaching signals in the order of 10-that arise from individual interband transitions of one quantum dot. As a result, we have developed an ultrafast optical tool for both manipulation and read-out of a single self-assembled quantum dot.

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“…Nonetheless, experiments have established various mechanisms for rapid relaxation of electrons from exited states to the ground states, such as the Auger-process and the multi-phonon process [328]. The observed relaxation time varies from tens of picoseconds to a few picoseconds [329,330]. The spin relaxation, especially for holes due to the large spin-orbit coupling, always accompanies with the energy relaxation, for the mixing in the excited states is much stronger than in the ground states.…”

Section: B Initialization By Entropy Dump To Phonon Bathsmentioning

confidence: 99%

Quantum computing by optical control of electron spins

Liu¹,

Yao²,

Sham³

2010

Advances in Physics

117

129

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We review the progress and main challenges in implementing large-scale quantum computing by optical control of electron spins in quantum dots (QDs). Relevant systems include self-assembled QDs of III-V or II-VI compound semiconductors (such as InGaAs and CdSe), monolayer fluctuation QDs in compound semiconductor quantum wells, and impurity centers in solids such as P-donors in silicon and nitrogen-vacancy centers in diamond. The decoherence of the electron spin qubits is discussed and various schemes for countering the decoherence problem are reviewed. We put forward designs of local nodes consisting of a few qubits which can be individually addressed and controlled. Remotely separated local nodes are connected by photonic structures (microcavities and waveguides) to form a large-scale distributed quantum system or a quantum network. The operation of the quantum network consists of optical control of a single electron spin, coupling of two spins in a local nodes, optically controlled quantum interfacing between stationary spin qubits in QDs and flying photon qubits in waveguides, rapid initialization of spin qubits, and qubit-specific single-shot non-demolition quantum measurement. The rapid qubit initialization may be realized by selectively enhancing certain entropy dumping channels via phonon or photon baths. The single-shot quantum measurement may be in-situ implemented through the integrated photonic network. The relevance of quantum non-demolition measurement to large-scale quantum computation is discussed. To illustrate the feasibility and demand, the resources are estimated for the benchmark problem of factorizing 15 with Shor's algorithm. *

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Spin-preserving ultrafast carrier capture and relaxation in InGaAs quantum dots

Abstract: Independent dynamic acousto-mechanical and electrostatic control of individual quantum dots in a LiNbO 3-GaAs hybrid

Cited by 27 publications

References 24 publications

Spatio-Temporal Dynamics of Carrier Capture Processes: Simulation of Optical Signals

Spatio-Temporal Dynamics of Carrier Capture Processes: Simulation of Optical Signals

Nonequilibrium carrier dynamics in self‐assembled InGaAs quantum dots

Quantum computing by optical control of electron spins

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