Multiqubit matter-wave interferometry under decoherence and the Heisenberg scaling recovery
Multiqubit matter-wave interferometry under decoherence and the Heisenberg scaling recovery
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DOI：
10.1103/physreva.99.033807
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发表时间：
2018-08
影响因子：
2.9
通讯作者：
Yanming Che;Jing Liu;X.-M. Lu;Xiaoguang Wang
中科院分区：
文献类型：
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作者：
Yanming Che;Jing Liu;X.-M. Lu;Xiaoguang Wang
到目前为止，大多数用于量子传感的物质波干涉测量（MWI）方案都是在无噪声的理想情况下进行评估的。在这项工作中，我们提供了在马尔可夫去相噪声下的通用多量子位MWI方案的评估。我们发现，对于具有非线性依赖于询问时间的尺度因子的某些类别的MWI方案，在独立和集体脱相情况下，最大纠缠探针的最佳精度随着粒子数的增加而降低。这一结果挑战了在消相拉姆齐型干涉仪中发现的传统智慧。我们首先研究了用于旋转传感的多量子位Sagnac原子干涉测量的最佳精度。我们发现，由于非常规询问时间二次相位积累和指数减相过程之间的竞争，Greenberger- Horne- Zeilinger （GHZ）状态（无噪声场景下的最优输入状态）导致大-$N$区域的量子Fisher信息消失。然后，我们的评估进一步扩展到具有纠缠态和退相干的量子传感的一般MWI方案。最后，初步分析了一种量子纠错逻辑GHZ态，该态具有恢复海森堡标度和提高灵敏度的潜力。
Most matter-wave interferometry (MWI) schemes for quantum sensing have so far been evaluated in ideal situations without noise. In this work, we provide assessments of generic multiqubit MWI schemes under Markovian dephasing noise. We find that, for certain classes of the MWI schemes with scale factors that are nonlinearly dependent on the interrogation time, the optimal precision of maximally entangled probes decreases with increasing particle number $N$, for both independent and collective dephasing situations. This result challenges the conventional wisdom found in dephasing Ramsey-type interferometers. We initiate the analyses by investigating the optimal precision of multiqubit Sagnac atom interferometry for rotation sensing. And we show that, due to the competition between the unconventional interrogation-time quadratic phase accumulation and the exponential dephasing processes, the Greenberger--Horne--Zeilinger (GHZ) state, which is the optimal input state in noiseless scenarios, leads to vanishing quantum Fisher information in the large-$N$ regime. Then our assessments are further extended to generic MWI schemes for quantum sensing with entangled states and under decoherence. Finally, a quantum error-correction logical GHZ state is tentatively analyzed, which could have the potential to recover the Heisenberg scaling and improve the sensitivity.