The scalability of quantum photonic integrated circuits opens the path towards large-scale quantum computing and communication. To date, this scalability has been limited by the stochastic nature of the quantum light sources. Moreover, hybrid integration of different platforms will likely be necessary to combine state-of-the-art devices into a functioning architecture. Here, we demonstrate the active alignment and edge-coupling of arrays of ten site-controlled gallium arsenide quantum dots to an array of ten silicon nitride single-mode waveguides, at cryogenic temperatures. The coupling is facilitated by the fabrication of nanopillars, deterministically self-aligned around each quantum dot, leading to a high-yield and regular array of single-photon sources. An on-chip beamsplitter verifies the triggered emission of single photons into the silicon nitride chip. The low inhomogeneous broadening of the ensemble enables us to observe the spectral overlap of adjacent site-controlled emitters. Across the array of waveguides, the signal collected from each coupled quantum dot is consistently and reproducibly 0.17 relative to the free-space collection from the very same single-photon source. Comparing measurement with waveguide simulations, we infer that absolute coupling efficiencies of $\approx 5 \%$ are currently obtained between our quantum dots and the waveguides.The scalability of quantum photonic integrated circuits opens the path towards large-scale quantum computing and communication. To date, this scalability has been limited by the stochastic nature of the quantum light sources. Moreover, hybrid integration of different platforms will likely be necessary to combine state-of-the-art devices into a functioning architecture. Here, we demonstrate the active alignment and edge-coupling of arrays of ten site-controlled gallium arsenide quantum dots to an array of ten silicon nitride single-mode waveguides, at cryogenic temperatures. The coupling is facilitated by the fabrication of nanopillars, deterministically self-aligned around each quantum dot, leading to a high-yield and regular array of single-photon sources. An on-chip beamsplitter verifies the triggered emission of single photons into the silicon nitride chip. The low inhomogeneous broadening of the ensemble enables us to observe the spectral overlap of adjacent site-controlled emitters. Across the array of waveguides, the signal collected from each coupled quantum dot is consistently and reproducibly 0.17 relative to the free-space collection from the very same single-photon source. Comparing measurement with waveguide simulations, we infer that absolute coupling efficiencies of $\approx 5 \%$ are currently obtained between our quantum dots and the waveguides.

physics.opticsCross-listedarXiv:2512.07535Dec 9, 2025

Quantum Computation on a Silicon Chip

Xiao, Yunfeng Yunfeng, Han +3 more

量子光学学报Jan 1, 20060 citations

Development of Quantum Computers with Electron Spins in Silicon Quantum Dots

Takashi Nakajima

Silicon is an excellent platform for integrating billions of quantum dots that serve as artificial atoms on a chip. We aim to use the electron spin state in a quantum dot as a qubit to realize a quantum computer, which potentially outperforms traditional supercomputers in certain tasks. However, practical quantum computation requires precise control of fragile qubit states and quantum error correction. We have investigated dominant error sources and implemented qubit control with low error rates, which opens the path toward fault-tolerant quantum computation.Silicon is an excellent platform for integrating billions of quantum dots that serve as artificial atoms on a chip. We aim to use the electron spin state in a quantum dot as a qubit to realize a quantum computer, which potentially outperforms traditional supercomputers in certain tasks. However, practical quantum computation requires precise control of fragile qubit states and quantum error correction. We have investigated dominant error sources and implemented qubit control with low error rates, which opens the path toward fault-tolerant quantum computation.

IEEE Electron Devices Technology & Manufacturing Conference (EDTM)Mar 1, 20260 citations

Quantum Computation in Semiconductor Quantum Dots

Daniel Loss

APSMar 1, 20010 citations

Leveraging off-the-shelf silicon chips for quantum computing

John Michniewicz, M. S. Kim

There is a growing demand for quantum computing across various sectors, including finance, materials, and studying chemical reactions. A promising implementation involves semiconductor qubits utilizing quantum dots within transistors. While academic research labs currently produce their own devices, scaling this process is challenging, requires expertise, and results in devices of varying quality. Some initiatives are exploring the use of commercial transistors, offering scalability, improved quality, affordability, and accessibility for researchers. This paper delves into potential realizations and the feasibility of employing off-the-shelf commercial devices for qubits. It addresses challenges such as noise, coherence, limited customizability in large industrial fabs, and scalability issues. The exploration includes discussions on potential manufacturing approaches for early versions of small qubit chips. The use of state-of-the-art transistors as hosts for quantum dots, incorporating readout techniques based on charge sensing or reflectometry, and methods like electron shuttling for qubit connectivity are examined. Additionally, more advanced designs, including 2D arrays and crossbar or DRAM-like access arrays, are considered for the path toward accessible quantum computing.There is a growing demand for quantum computing across various sectors, including finance, materials, and studying chemical reactions. A promising implementation involves semiconductor qubits utilizing quantum dots within transistors. While academic research labs currently produce their own devices, scaling this process is challenging, requires expertise, and results in devices of varying quality. Some initiatives are exploring the use of commercial transistors, offering scalability, improved quality, affordability, and accessibility for researchers. This paper delves into potential realizations and the feasibility of employing off-the-shelf commercial devices for qubits. It addresses challenges such as noise, coherence, limited customizability in large industrial fabs, and scalability issues. The exploration includes discussions on potential manufacturing approaches for early versions of small qubit chips. The use of state-of-the-art transistors as hosts for quantum dots, incorporating readout techniques based on charge sensing or reflectometry, and methods like electron shuttling for qubit connectivity are examined. Additionally, more advanced designs, including 2D arrays and crossbar or DRAM-like access arrays, are considered for the path toward accessible quantum computing.

arXiv:2406.03328Applied Physics LettersJun 24, 20245 citations

\approx 5 \%

are currently obtained between our quantum dots and the waveguides.