Squeezing by critical speeding up: Applications in quantum metrology
Squeezing by critical speeding up: Applications in quantum metrology
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DOI：
10.1103/physreva.105.042620
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发表时间：
2022-04-28
影响因子：
2.9
通讯作者：
Gietka, Karol
中科院分区：
文献类型：
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作者：
Gietka, Karol
我们提出了一个替代协议，允许准备的关键状态，而不是遭受的关键减速的好处，从关键的加速。巧合的是，我们通过远离临界点来准备这些状态，这允许加速。我们将该协议应用于典型的量子Rabi模型及其经典振子极限以及Lipkin-Meshkov-Glick模型。随后，我们讨论了绝热加速协议在量子计量中的应用，并将其性能与临界量子计量进行了比较。我们表明，临界量子计量与Lipkin-Meshkov-Glick模型甚至不能克服标准的量子极限，我们认为，即使临界计量协议可以克服它在某些情况下，临界计量是一个次优的策略。最后，我们得出结论，从量子技术的角度来看，表现出相变的系统确实很有趣;然而，它可能不是应该引起最多注意的临界点。
We present an alternative protocol allowing for the preparation of critical states that instead of suffering from the critical slowing down benefits from the critical speeding up. Paradoxically, we prepare these states by going away from the critical point which allows for the speed-up. We apply the protocol to the paradigmatic quantum Rabi model and its classical oscillator limit as well as the Lipkin-Meshkov-Glick model. Subsequently, we discuss the application of the adiabatic speed-up protocol in quantum metrology and compare its performance with critical quantum metrology. We show that critical quantum metrology with the Lipkin-Meshkov-Glick model cannot even overcome the standard quantum limit, and we argue that, even though critical metrology protocols can overcome it in some cases, critical metrology is a suboptimal metrological strategy. Finally, we conclude that systems exhibiting a phase transition are indeed interesting from the viewpoint of quantum technologies; however, it may not be the critical point that should attract the most attention.