School of Physics, International Joint Laboratory on Quantum Sensing and Quantum Metrology, Hubei Key Laboratory of Gravitation and Quantum Physics, Institute for Quantum Science and Engineering, Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China.
Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China.
Phys Rev Lett. 2023 Apr 28;130(17):170801. doi: 10.1103/PhysRevLett.130.170801.
Surpassing the standard quantum limit and even reaching the Heisenberg limit using quantum entanglement, represents the Holy Grail of quantum metrology. However, quantum entanglement is a valuable resource that does not come without a price. The exceptional time overhead for the preparation of large-scale entangled states raises disconcerting concerns about whether the Heisenberg limit is fundamentally achievable. Here, we find a universal speed limit set by the Lieb-Robinson light cone for the quantum Fisher information growth to characterize the metrological potential of quantum resource states during their preparation. Our main result establishes a strong precision limit of quantum metrology accounting for the complexity of many-body quantum resource state preparation and reveals a fundamental constraint for reaching the Heisenberg limit in a generic many-body lattice system with bounded one-site energy. It enables us to identify the essential features of quantum many-body systems that are crucial for achieving the quantum advantage of quantum metrology, and brings an interesting connection between many-body quantum dynamics and quantum metrology.
利用量子纠缠超越标准量子极限,甚至达到海森堡极限,是量子计量学的圣杯。然而,量子纠缠是一种有价值的资源,并非免费可得。大规模纠缠态的制备需要极高的时间开销,这令人担忧地引发了对海森堡极限是否能够从根本上实现的质疑。在这里,我们发现了 Lieb-Robinson 光锥为量子 Fisher 信息增长所设定的通用速度限制,用于刻画量子资源态在制备过程中的计量潜力。我们的主要结果建立了量子计量学的强精度限制,考虑了多体量子资源态制备的复杂性,并揭示了在具有有限单站点能量的一般多体晶格系统中达到海森堡极限的基本约束。它使我们能够识别出实现量子计量学量子优势的关键特征,以及多体量子动力学和量子计量学之间的有趣联系。