Spin-Qubit Arrays and Shuttling
Spin shuttling with gapless scheduling of real-time parametrized pulses
3:48 pm – 4:00 pmSpin qubits are promising for scalable quantum computation due to their long coherence times, compact footprint, and compatibility with industrial foundries. Increasing connectivity across processors can be achieved by physically relocating qubits. Recent advances have focused on coherent shuttling of spins to enable transport over extended distances, though high fidelity transfer remains challenging.
Conveyor mode shuttling uses a traveling wave potential, demonstrating improved spin coherence. This method is challenging due to the need for precise control over the phase and frequency of multiple signals applied to successive electrodes. Furthermore, dynamic directional control is possible by reversing the signal frequency, which enhances the effectiveness of parameterizing sinusoidal signals. Shuttling is therefore traditionally performed by precalculating these large waveform sequences into memory banks of arbitrary waveform generators. This is not a scalable approach due to memory requirements, and long compilation and upload overhead. We solve this in the Qblox control modules with gapless play of consecutive pulses with instantaneous updating of the frequency parameter in between. This capability is demonstrated for “bucket brigade” and “conveyor-mode” spin shuttling in [1].
We further advance spin qubit research by providing a hardware platform that combines all control and readout tasks. This is operated by a software suite that gives direct access to complex tuning steps like the mitigation of cross-capacitance, microwave crosstalk, and Bias-T signal distortion.