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arXiv · 2511.16051

TRAM: A Transverse Relaxation Time-Aware Qubit Mapping Algorithm for NISQ Devices

Yifei Huang·Pascal Jahan Elahi·Ugo Varetto·Kan He·Jinchuan Hou·Shusen Liu
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Abstract

Noisy intermediate-scale quantum (NISQ) devices impose dual challenges on quantum circuit execution: limited qubit connectivity requires extensive SWAP-gate routing, while time-dependent decoherence progressively degrades quantum information. Existing qubit mapping algorithms optimize for hardware topology and static calibration metrics but systematically neglect transverse relaxation dynamics (T2), creating a fundamental gap between compiler decisions and evolving noise characteristics. We present TRAM (Transverse Relaxation Time-Aware Qubit Mapping), a coherence-guided compilation framework that elevates decoherence mitigation to a primary optimization objective. TRAM integrates calibration-informed community detection to construct noise-resilient qubit partitions, generates time-weighted initial mappings that anticipate coherence decay, and dynamically schedules SWAP operations to minimize cumulative error accumulation. Evaluated on Qiskit-based simulators with realistic noise models, TRAM outperforms SABRE by 3.59% in fidelity, reduces gate count by 11.49%, and shortens circuit depth by 12.28%, establishing coherence-aware optimization as essential for practical quantum compilation in the NISQ era.

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Yifei Huang, Pascal Jahan Elahi, Ugo Varetto, Kan He, Jinchuan Hou, Shusen Liu. 2025-11-20. TRAM: A Transverse Relaxation Time-Aware Qubit Mapping Algorithm for NISQ Devices. https://arxiv.org/abs/2511.16051

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