Towards Efficient Single Photon Generation from a Single Ion Coupled to a Fibre Cavity in a Linear Trap
ORAL
Abstract
This research represents a significant step toward the efficient generation of flying qubits from stationary qubits, a key capability for enhancing the scalability and interconnectivity of modern quantum computers. We employ calcium ions confined in a 3D linear ion trap and the photons emitted by these ions serve as the interconnection medium for quantum communication.
Our approach is to couple a single ion within a linear chain to a fibre-based Fabry–Pérot cavity, oriented with its cavity axis perpendicular to the trap axis to achieve individual ion–cavity coupling. Such a configuration has not been previously demonstrated due to the substantial disruption to the trapped ions induced by the nearby dielectric mirrors. To overcome this challenge, we developed an active potential compensation method in combination with a dual-RF driving scheme.
Experimentally, we have completed the construction of our setup. Our monolithic miniaturized linear Paul trap was fabricated from glass using selective laser etching (SLE). The fibre mirror substrates were fabricated in-house via an automated CO₂ laser machining process and mirror-coated to the desired reflectivity. The assembled system exhibits a measured cavity finesse of approximately 50,000, corresponding to a coupling strength of g=2π×9.06 MHz, which leads to a cooperativity C of 0.94. Taking the efficiency parameters into account, a single-photon collection rate potentially up to 67.5 kHz can be achieved, which is over two orders of magnitude higher than that achievable without cavity enhancement.
Looking forward, the integration of the fibre cavity enables two promising directions. First, it facilitates the realization of a photonic-interconnected modular quantum computer, comprising multiple linear-trap modules linked via optical channels, thereby substantially increasing the accessible qubit number. Second, it lays the foundation for a cavity-mediated, photon-based quantum network. Collectively, these advances represent a pivotal step toward the practical realization of large-scale quantum computing.
Our approach is to couple a single ion within a linear chain to a fibre-based Fabry–Pérot cavity, oriented with its cavity axis perpendicular to the trap axis to achieve individual ion–cavity coupling. Such a configuration has not been previously demonstrated due to the substantial disruption to the trapped ions induced by the nearby dielectric mirrors. To overcome this challenge, we developed an active potential compensation method in combination with a dual-RF driving scheme.
Experimentally, we have completed the construction of our setup. Our monolithic miniaturized linear Paul trap was fabricated from glass using selective laser etching (SLE). The fibre mirror substrates were fabricated in-house via an automated CO₂ laser machining process and mirror-coated to the desired reflectivity. The assembled system exhibits a measured cavity finesse of approximately 50,000, corresponding to a coupling strength of g=2π×9.06 MHz, which leads to a cooperativity C of 0.94. Taking the efficiency parameters into account, a single-photon collection rate potentially up to 67.5 kHz can be achieved, which is over two orders of magnitude higher than that achievable without cavity enhancement.
Looking forward, the integration of the fibre cavity enables two promising directions. First, it facilitates the realization of a photonic-interconnected modular quantum computer, comprising multiple linear-trap modules linked via optical channels, thereby substantially increasing the accessible qubit number. Second, it lays the foundation for a cavity-mediated, photon-based quantum network. Collectively, these advances represent a pivotal step toward the practical realization of large-scale quantum computing.
*This work was supported by the JST Moonshot R&D (Grant Number JPMJMS2063) and MEXT Quantum Leap Flagship Program (MEXT Q-LEAP) (Grant NumberJPMXS0118067477).
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Presenters
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Zhenghan Yuan
- Okinawa Insitute of Science and Technology