QLC: EAGER: Collaborative Research: New Design for Quantum Chemistry Calculations on Emerging Quantum Computers

乔治城大学的James Freericks和西北大学的Dominika Zgid获得了化学系化学理论、模型和计算项目的Eager奖，他们开发了在量子计算机上解决量子化学问题的方法。计算机经常被用来预测不同的科学现象。在量子化学中，它们被用来确定分子的总能量，分子如何振动和旋转，它如何与光相互作用，以及它在化学反应中如何变化。一些量子化学问题很难用最强大的超级计算机来解决。幸运的是，一个新的计算时代正在来临。全新类型的计算机，称为量子计算机，现在正在作为早期的原型机制造。这些量子计算机是在使用量子力学进行操作的范例中编程的。因此，它们非常适合解决棘手的量子化学问题。Freericks， Zgid和他们的同事设计了如何在这些量子计算机上解决一系列不同的量子化学问题的策略。该项目正在从零开始设计算法，当合适的机器可用时，将在量子计算机上进行测试。这项工作的广泛影响包括将本科生、高中生和公民科学家引入量子计算机上的量子化学领域。它还支持了一本名为《没有微积分的量子力学》的量子书中化学主题的一些发展。这个项目的重点是使用混合量子-经典方法来解决量子化学问题。量子计算机用于确定强量子相互作用的效果，而传统计算机用于计算如何最好地初始化量子计算机以及如何将量子计算机的结果纳入确定最终答案。随着量子硬件质量的提高，允许适度的电路深度，这项工作采用了格林的函数方法，大大提高了计算的准确性和效率。这项工作的最终产物将是量子计算机描述复杂量子化学现象的可行性的准确演示。最初的重点是小型化学系统，如CrH二聚体，可以在16量子位机器上模拟，然后将扩展到更复杂的系统，如（NiO）2和（NiO）4，如硬件和算法的发展允许。与工业界的合作将在基于超导的量子计算机（如IBM现有的量子计算机）和基于离子阱的量子计算机（如IonQ正在开发的量子计算机）上运行较低电路深度的算法。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

James Freericks of Georgetown University and Dominika Zgid of Northwestern University are supported by an Eager award from the Chemical Theory, Models and Computational program in the Division of Chemistry to develop approaches to solve quantum chemistry problems on quantum computers. Computers are often employed to make predictions of different scientific phenomena. In quantum chemistry, they are employed to determine the total energy of a molecule, how the molecule vibrates and rotates, how it interacts with light, and how it changes in a chemical reaction. Some quantum chemistry problems are too difficult to be solved with even the most powerful supercomputer. Fortunately, a new age in computing is dawning. Completely new types of computers, called quantum computers, are now being made as early prototype machines. These quantum computers are programmed within a paradigm that uses quantum mechanics for their operation. Hence, they are well suited to tackle solving difficult quantum chemistry problems. Freericks, Zgid and their coworkers design strategies for how to solve a range of different quantum chemistry problems on these quantum computers. The project is designing algorithms from scratch which will be tested on quantum computers when appropriate machines become available. The broader impact of this work includes introducing undergraduates, high school students, and citizen scientists to the field of quantum chemistry on quantum computers. The also supports some development of chemistry topics in a quantum book entitled Quantum Mechanics without Calculus. This project focuses on using a hybrid quantum-classical approach to solving quantum chemistry problems. The quantum computer is employed to determining the effect of strong quantum interactions, while the conventional computer is used to calculate how best to initialize the quantum computer and how to incorporate the results from the quantum computer into determining the final answers. The work employs Green's function methods to vastly improve the accuracy and efficiency of the calculations as the quality of the quantum hardware improves to allow moderate circuit depth. The end-product of this work will be an accurate demonstration of the viability of quantum computers to describe complex quantum chemical phenomena. The initial focus is on small chemical systems like the CrH dimer, which can be simulated on a 16-qubit machine, and then will expand to more complicated systems, such as (NiO)2 and (NiO)4, as hardware and algorithmic developments allow. Partnerships with industry will run the lower circuit depth algorithms on superconducting-based quantum computers, such as those available at IBM, and on ion-trap-based quantum computers, such as those being developed at IonQ.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.