Optical pumping and initialization of a hole spin in site-controlled InGaAs pyramidal quantum dots

Abstract

We investigate site-controlled In${}_{0.25}$Ga${}_{0.75}$As quantum dots in (111)B GaAs pyramidal recesses as spin qubits. Combining scanning confocal cryomicroscopy, magneto-photoluminescence studies and resonant excitation, we identify and isolate a positively charged exciton with a hole-spin in its ground state. Application of a strong 5 T magnetic field parallel to the growth axis, induces a fourfold splitting of the energy levels of the positively charged exciton creating an optically addressable double-lambda system. We combine weak above-band and resonant excitation to demonstrate spin pumping and high-fidelity spin initialization through all four optical transitions and study the system behavior as a function of the resonant driving strength showing the existence of a robust spin that can be optically pumped and initialized. These results demonstrate the potential of these quantum dots for precise spin manipulation and their relevance for future quantum hardware.

arXiv comment6 Pages, 4 Figures

References in corpus (14)

• Towards quantum dot arrays of entangled photon emitters
• Semiconductor devices for entangled photon pair generation: a review
• A site-controlled quantum dot system offering both high uniformity and spectral purity
• Fast initialization of the spin state of an electron in a quantum dot in the Voigt configuration
• Dark-bright mixing of interband transitions in symmetric semiconductor quantum dots
• Conditions for entangled photon emission from (111)B site-controlled Pyramidal quantum dots
• Single-shot initialization of electron spin in a quantum dot using a short optical pulse
• Observation of resonance fluorescence and the Mollow-triplet from a coherently driven site-controlled quantum dot
• Magnetic field induced valence band mixing in [111] grown semiconductor quantum dots
• Complex optical signatures from quantum dot nanostructures and behavior in inverted pyramidal recesses
• Initialization of a spin qubit in a site-controlled nanowire quantum dot
• Indium segregation during III-V quantum wire and quantum dot formation on patterned substrates
• Hole Spin Pumping and Re-pumping in a p-type δ-doped InAs Quantum Dot
• Operation of a Continuous Flow Liquid Helium Magnetic Microscopy Cryostat as a Closed Cycle System

Cited by in corpus (1)

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