Speaker
Description
Roadmaps for next-generation trapped ion quantum computers are built on distributed architectures, where qubits are shuttled between different zones for loading, gates and readout. When the ion is shuttled, changes in the magnetic field environment can lead to the spin on the ion accumulating a phase dependent on the transport path and duration. As the number of qubits on commercially available quantum processors increases, the total duration of circuit time occupied by shuttling increases. If the shuttling phase is not corrected, ion transport can become a significant source of error as transport becomes a larger overhead on wider quantum circuits.
A method to characterise this transport phase is demonstrated that offers some robustness to calibration errors, whilst achieving phase resolution beyond the standard quantum limit. To mitigate the error, phase-compensation can be utilised in which applying a virtual Z-gate cancels the phase accumulated during transport without requiring pulsed dynamical decoupling. Quantum state tomography can be used to validate the error model. Finally, randomised benchmarking of the Clifford-1 group can characterise the error attributed to shuttling, where the phase is left uncorrected compared with phase compensation (if needed).
| Academic level | PhD student |
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