Speaker
Description
Progress in trapped-ion quantum computers depends on developing scalable, high-fidelity control of trapped-ion qubits. Laser-based systems have demonstrated high-fidelity, all-to-all connectivity at small scales [1]. However, the practicality of scaling complex, high-precision laser systems remains uncertain. An alternative approach for manipulating hyperfine qubits is to drive transitions directly using microwaves. Microwave technology is mature, offers a high degree of control, and can be directly integrated into chip-based ion traps. Additionally, microwave-driven trapped-ion qubits have achieved the highest-fidelity single-qubit [2] and two-qubit gates of any platform [3, 4].
Here, we report on the development of a closed-cycle cryostat system for manipulating trapped $^{43}\mathrm{Ca}^+$ ions. The goal of this system is to enable rapid turnaround for testing novel trap architectures. We have set up a multi-stage cryogenic system that can be fully cycled in 48–72 hours. The system supports all lasers required for state preparation and measurement of $^{43}\mathrm{Ca}^+$. We have also installed and tested a thermal oven for ion loading. In parallel, building on [1], we have designed, developed, and characterised a new high-fidelity microwave drive, with the aim of pushing gate operations to even higher fidelities.
[1] Ransford, A. et al. (2025) Helios: A 98-qubit trapped-ion quantum computer.
[2] M.C. Smith, A. D. Leu, et al., Phys. Rev. Lett., 134, 230601 (2025)
[3] A. C. Hughes et. al., arXiv:2510.17286 (2025)
[4] R. Srinivas et. al., Nature, 597, 209-213 (2021)
| Academic level | PhD student |
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