Large Baseline Quantum-Enhanced Imaging Networks

成像和参数估计是大多数现代科学的基础，改进的成像技术的发展将在科学和文化上产生极其广泛的影响。目前的成像技术受到孔径大小、损耗和系统噪声的限制，但最近的结果表明，利用量子计量学的技术可以克服衍射限制。实现量子增强计量学需要可靠的大规模纠缠态来源。然而，这种状态极其脆弱，很容易被环境噪声破坏。因此，量子增强传感的演示目前仅限于实验室环境。与此同时，物理学家正在建造越来越大的量子网络，承诺进行安全通信和分发量子计算。量子网络提供的资源允许量子状态从一个位置转移到另一个位置，在那里相位和幅度信息都被忠实地复制。将量子互联网在空间上分离的共享量子资源与大规模成像的要求相结合，我们可以设计出原则上可以实现高出许多个数量级的成像分辨率的协议。在这个理论提案中，我们开发了在量子网络上执行2D和3D成像和传感的最佳架构，具有通过专用量子纠错协议减少损失和噪声的能力。同时，我们将设计非相干成像处理方法，使人们能够在光学频率上实现极大的基线(例如，地球直径或更大)。我们首先建立了高精度时间测量的理论，为进行时钟同步和目标测距/检测提供了可能。然后，我们在远距离站点之间建立共享的相位参考，允许对在成像孔径远端收集的信号进行相干处理。然后，我们将使用大型网络进行成像，通过量子纠错集成丢失和噪声保护。最后，我们探索了训练量子干涉仪用于物体识别的方法，包括热态和纠缠态。因此，该项目消除了目前通过测量优化以及状态优化(包括量子纠错)进行成像和参数估计的限制。该项目的雄心勃勃的目标是将量子成像、量子计量学和量子通信联系起来，对整个量子技术领域产生深远影响。它提出了一种关于大基线2D和3D量子成像和计量学的新颖、统一的理论，该理论将与昆士兰大学(澳大利亚)、埃尔兰根大学(德国)和布里斯托尔大学(英国)的实验专业知识紧密结合。其结果将带来低噪声探测器、高精度测量和超分辨率图像，这是由创新的实验设计实现的。该系统将特别适合在高噪声环境下运行，应用于恒星干涉测量和测距；它们将直接影响英国将量子信息用于密码应用、导航系统、现场传感器和通信技术。

Imaging and parameter estimation underpin most of modern science, and the development of improved imaging techniques will have an extremely broad impact, scientifically and culturally. Current imaging techniques are limited by aperture size, losses, and system noise, but recent results show that the diffraction limit can be overcome by employing techniques from quantum metrology. The realisation of quantum-enhanced metrology requires reliable sources of large-scale entangled states. However, such states are extremely fragile and are easily destroyed by environmental noise. As such, demonstrations of quantum-enhanced sensing are presently limited to a laboratory setting.Meanwhile, physicists are building ever-larger quantum networks, with the promise of secure communication and distributing quantum computing. Quantum networks provide resources that allow the transfer of quantum states from one location to another, where both phase and amplitude information is faithfully reproduced. Combining the spatially separated shared quantum resources of the Quantum Internet with the requirements of large-scale imaging, we can devise protocols that in principle achieve imaging resolution that is many orders of magnitude better. In this theoretical proposal we develop the optimal architecture for performing 2D and 3D imaging and sensing on a quantum network, with the ability to mitigate loss and noise via dedicated quantum error correction protocols. In parallel, we will devise incoherent imaging processing methods, allowing one to achieve extremely large baselines, (e.g., the diameter of the Earth or larger) at optical frequencies. We first construct the theory for high-accuracy time measurements, which opens up the possibility to perform clock synchronization and perform target ranging/detection. Then we establish shared phase references between distant sites, allowing coherent processing of signals collected at far ends of our imaging aperture. Then, we will use large networks to perform imaging, integrated with loss and noise protection via quantum error correction. Lastly, we explore methods to train a quantum interferometer for object recognition for both thermal and entangled states. Thus, the project removes the current limitations of imaging and parameter estimation by measurement optimisation, as well as state optimisation (including quantum error correction).This project has the ambitious goal of linking quantum imaging, quantum metrology and quantum communication, with a profound impact on the whole field of quantum technologies. It presents a novel, unified theory on large-baseline 2D and 3D quantum imaging and metrology that will be tightly combined with the experimental expertise of the Universities of Queensland (Australia), Erlangen (Germany), and Bristol (UK). The result will bring about low-noise detectors, highly accurate measurements, and super-resolved images, enabled by innovative experimental designs. The systems will be particularly suited to operate in a high-noise environment, with applications to stellar interferometry, and ranging; they will directly impact the UK's use of quantum information for cryptographic applications, navigation systems, field sensors, and communication technologies.