Simulating Electron - Phonon Processes with Photonics

量子计算有望通过提供计算机来彻底改变计算化学领域，这些计算机的大小沿着呈指数级增长，并且它们的目标是模拟系统。然而，虽然已经提出了许多有前途的算法，用于在量子计算机上进行计算化学计算，但其中大多数算法需要的量子位和门数远远超出了目前实验上可用的数量。此外，虽然存在用于实现量子技术的许多不同架构，但光子学（操纵单个光子的过程）已将其自身确立为用于提供近期量子优势的领先架构之一。玻色子和高斯玻色子采样等技术为量子优势提供了清晰的途径，实验开销相对较低。通过这个项目，我们希望建立可以利用光子学的相对实验简单性的算法，以便为计算化学提供近期的量子优势。该项目的目标是提出可用于计算化学的算法，这些算法可以在近期量子光子器件上实现。在这个项目中，我们希望建立在以前的工作，这表明了技术的适用性，如高斯玻色子采样量子化学提出算法，找到更普遍的适用性量子化学，特别是那些在电子结构理论和电子玻色子结构理论。电子-声子相互作用被认为是造成广泛现象的原因，然而从从头算方法模拟和预测它们仍然具有挑战性。我们希望提出低实验成本的技术可以用来模拟这些系统，从而提供新的见解，他们的工作方式。我们的目标是利用量子光子学的原生技术来提出模拟风格的量子器件，这些量子器件可以用于模拟量子化学，而不需要大的量子位/门计数。以前的工作已经表明，高斯玻色子采样可以用来模拟分子的振动光谱，而在这里，我们看看玻色子采样（和其他相关技术）是否可以应用于更广泛的计算化学问题。光子学提供了一个奇妙的“工具箱”的技术，我们希望找到方法应用于计算化学，希望提供算法与短期实施。在整个项目中，我们希望与光子硬件团体和公司合作，实现我们提出的算法。我们目前正在与Duality Quantum Photonics合作，实施一种新的算法，用于解决线性光学电子结构理论中的问题，并希望在整个项目中继续合作。该项目属于EPSRC量子技术研究领域的福尔斯。

Quantum computing promises to revolutionise the field of computational chemistry by providing computers which scale exponentially in size along with the systems they aim to model. However, whilst many promising algorithms for performing computational chemistry calculations on quantum computers have been proposed most of these require qubit and gate counts far beyond what is currently available experimentally. Additionally, whilst many different architectures for implementing quantum technologies exist, photonics, the process of manipulating individual photons, has established itself as one of the leading architectures for providing near term quantum advantage. Techniques such as boson and gaussian boson sampling offer clear routes to quantum advantage with relatively low experimental overheads. With this project we hope to build algorithms which can utilise the relative experimental simplicity of photonics in order to provide near term quantum advantage for computational chemistry. The objective of the project is to propose algorithms useful for computational chemistry which can be implemented on near term quantum photonic devices. In this project we look to build on previous work which has shown the applicability of techniques such as gaussian boson sampling to quantum chemistry to propose algorithms which find more general applicability for quantum chemistry, particularly those in electronic structure theory and electron-boson structure theory. Electron - phonon interactions are posited to be responsible for a wide range of phenomena however simulating and predicting them from ab-initio methods remains challenging. We hope to propose ways in which low experimental cost techniques can be used to simulate these systems and thus offer new insights into their working. We aim to exploit techniques native to quantum photonics to propose analog style quantum devices which can be used to simulate quantum chemistry without the need to large qubit / gate counts. Previous work has shown that gaussian boson sampling can be used to simulate the vibrational spectra of molecules whereas here we look to see whether boson sampling (and other related techniques) can be applied to more broader problems in computational chemistry. Photonics offers a fantastic "toolbox" of techniques which we hope to find ways to apply to computational chemistry in the hopes of providing algorithms with near term implementations. Throughout this project we hope to collaborate with photonic hardware groups and companies to implement our proposed algorithms. We are currently involved with a collaboration with Duality Quantum Photonics to implement a novel algorithm for solving problems in electronic structure theory with linear optics and hope to continue the collaboration throughout the project. This project falls within the EPSRC quantum technologies research area.