CAMEL: Physically Inspired Crosstalk-Aware Mapping and Gate Scheduling for Frequency-Tunable Quantum Chips

Abstract

Crosstalk poses a significant challenge in quantum computing, particularly when quantum gates are executed in parallel, as qubit frequency resonance can lead to residual coupling and reduced gate fidelity. Current solutions struggle to mitigate both crosstalk and decoherence during parallel two-qubit gate operations on frequency-tunable quantum chips. To address this, we propose a crosstalk-aware mapping and gate scheduling (CAMEL) approach, designed to mitigate crosstalk and suppress decoherence by leveraging the tunable coupler’s physical properties and incorporating a pulse compensation technique. CAMEL operates within a two-step compilation framework: first, a qubit mapping strategy that considers both crosstalk and decoherence; and second, a gate timing scheduling method that prioritizes the execution of the largest possible set of crosstalk-free parallel gates, reducing overall circuit execution time. Evaluation results demonstrate CAMEL’s superior ability to mitigate crosstalk compared to crosstalk-agnostic methods, while successfully suppressing decoherence where other approaches fail. Additionally, CAMEL performs better than dynamic-frequency-aware techniques, particularly in low-complexity hardware environments.