Research paperExperimental GrowthExperimental CharacterizationOptical pumping and initialization of a hole spin in site-controlled InGaAs pyramidal quantum dotsR. A. Barcan, I. Samaras, K. Barr, G. Juska et al.2025·10.1103/fps4-vb8c·arXiv:2503.05400AbstractWe investigate site-controlled In0.25Ga0.75As 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.Read more
Site-controlled In0.25Ga0.75As quantum dots grown in tetrahedral pyramidal recesses on a (111)B GaAs substrate.1 characterization2 properties3 figuresExperimentalIn0.25Ga0.75AsStudied MaterialGaAsSubstrate / DielectricExpand
Research paperExperimental GrowthExperimental CharacterizationOptical pumping and initialization of a hole spin in site-controlled InGaAs pyramidal quantum dotsR. A. Barcan, I. Samaras, K. Barr, G. Juska et al.2025·10.1103/fps4-vb8c·arXiv:2503.05400AbstractWe investigate site-controlled In0.25Ga0.75As 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.Read more
Site-controlled In0.25Ga0.75As quantum dots grown in tetrahedral pyramidal recesses on a (111)B GaAs substrate.1 characterization2 properties3 figuresExperimentalIn0.25Ga0.75AsStudied MaterialGaAsSubstrate / DielectricExpand
Research paperExperimental GrowthExperimental CharacterizationOptical pumping and initialization of a hole spin in site-controlled InGaAs pyramidal quantum dotsR. A. Barcan, I. Samaras, K. Barr, G. Juska et al.2025·10.1103/fps4-vb8c·arXiv:2503.05400AbstractWe investigate site-controlled In0.25Ga0.75As 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.Read more
Site-controlled In0.25Ga0.75As quantum dots grown in tetrahedral pyramidal recesses on a (111)B GaAs substrate.1 characterization2 properties3 figuresExperimentalIn0.25Ga0.75AsStudied MaterialGaAsSubstrate / DielectricExpand
Research paperExperimental GrowthExperimental CharacterizationOptical pumping and initialization of a hole spin in site-controlled InGaAs pyramidal quantum dotsR. A. Barcan, I. Samaras, K. Barr, G. Juska et al.2025·10.1103/fps4-vb8c·arXiv:2503.05400AbstractWe investigate site-controlled In0.25Ga0.75As 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.Read more
Site-controlled In0.25Ga0.75As quantum dots grown in tetrahedral pyramidal recesses on a (111)B GaAs substrate.1 characterization2 properties3 figuresExperimentalIn0.25Ga0.75AsStudied MaterialGaAsSubstrate / DielectricExpand