Crosstalk-mitigated microelectronic control for optically-active spins

TL;DR

This paper introduces a microelectronic control scheme that mitigates microwave crosstalk in densely packed solid-state qubits, enabling scalable quantum information processing with improved coherence and control.

Contribution

The authors develop and demonstrate a foundry microelectronics-based crosstalk mitigation method for closely spaced solid-state spins without qubit detuning.

Findings

Crosstalk can be reduced to undetectable levels using active cancellation.

Achieved 10 MHz Rabi oscillations at milliwatt microwave power.

Enhanced qubit control and coherence under crosstalk mitigation.

Abstract

To exploit the sub-nanometre dimensions of qubits for large-scale quantum information processing, corresponding control architectures require both energy and space efficiency, with the on-chip footprint of unit-cell electronics ideally micron-scale. However, the spin coherence of qubits in close packing is severely deteriorated by microwave crosstalk from neighbouring control sites. Here, we present a crosstalk-mitigation scheme using foundry microelectronics, to address solid-state spins at sub-100 $\mu$m spacing without the need for qubit-detuning. Using nitrogen-vacancy centres in nanodiamonds as qubit prototypes, we first demonstrate 10 MHz Rabi oscillation at milliwatts of microwave power. Implementing the active cancellation, we then prove that the crosstalk field from neighbouring lattice sites can be reduced to undetectable levels. We finally extend the scheme to show increased qubit control, or effectively, the spin coherence under crosstalk mitigation. Compatible with integrated optics, our results present a step towards scalable control across quantum platforms using silicon microelectronics.