NSF-BSF: Many-Body Physics of Quantum Computation

该奖项支持研究、教育和推广活动，目的是发展理论基础和特定的量子算法，这些算法可以在现代量子计算平台上实现。过去十年见证了原型量子计算机的开发和制造取得了巨大进步。尽管仍然存在噪声，并且容易出现误差和退相干，但它们已经能够执行重要的任务。这带来了对有意义的计算问题的探索，这些问题可以在可用量子架构的帮助下解决。其中一个问题是优化，即找到一个结果（即一个比特序列），它优化了一组复杂的标准（称为成本函数）。从物理学的角度来看，这是一个寻找无序介质（即玻璃）的低能态（即冷却）的问题。该项目将利用可用的量子比特平台实现这种玻璃景观，并利用其组成元素的量子动力学开发冷却协议。人们认识到理想量子极大地促进了冷却。该项目将研究现实生活中噪声耗散量子比特阵列完成这些任务的有效性。它将开发特定的算法，在商用设备上实现它们（利用NSF云银行资助机制），并将它们的性能与理论预期进行比较。该奖项还促进了PI的教育和推广活动，通过开发量子计算课程，准备评论文章，组织研讨会和暑期学校，为美国STEM劳动力的发展做出贡献。该奖项支持研究、教育和推广活动，目的是为特定的量子算法开发理论和协议，这些理论和协议可以通过NSF云银行在商业平台上实施。在理论方面，量子比特阵列代表了开放耗散量子系统的例子，它是由时变局部场和耦合驱动的。这种驱动耗散的环境可以用林德布拉迪亚模型来模拟。该项目将扩展非平衡量子场论的理论工具，纳入林德布拉迪亚动力学。该构造的目的之一是阐明阵列希尔伯特空间中多体局部化转换的存在性和性质。了解这种跃迁对于开发有效量子冷却（即近似量子优化）的协议至关重要。具体来说，玻璃化多体局域相的冷却可以通过一阶跃迁的周期性量子熔化和二阶跃迁的再冻结来实现。该项目将开发这种耗散冷却循环的理论，并在D-Wave 5000量子比特平台上实现它们。它还将开发用于分析由此产生的“实验”数据集的工具。该奖项还促进了PI的教育和推广活动，通过开发量子计算课程，准备评论文章，组织研讨会和暑期学校，为美国STEM劳动力的发展做出贡献。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。

NONTECHNICAL SUMMARYThis award supports research, education, and outreach activities with a goal to develop theoretical underpinnings and specific quantum algorithms, which may be implemented on the modern-day quantum computation platforms. The last decade witnessed a tremendous progress in the development and manufacturing of prototypical quantum computers. Though still noisy and subject to errors and decoherence, they are already capable of performing non-trivial tasks. This brought a quest for meaningful computational problems, which may be tackled with the help of available quantum architecture. One such problem is optimization, that is finding an outcome (i.e. a sequence of bits), which optimizes a certain intricate set of criteria (known as a cost function). From the physics perspective, this is a problem of finding low energy states (i.e. cooling) of a disordered media (aka glass). The project will implement such glassy landscapes with available qubit platforms and develop cooling protocols utilizing the quantum dynamics of their constituent elements. It was realized that the ideal quantumness greatly facilitates cooling. The project will investigate the effectiveness of real-life noisy-dissipative qubit arrays to accomplish these tasks. It will develop specific algorithms, implement them on commercially available devices (utilizing the NSF Cloud Bank funding mechanism) and compare their performance with theoretical expectations. The award also facilitates the PI's educational and outreach activities which contribute to the development of the US STEM workforce through development of quantum computation curriculum, preparing review articles, organization of workshops, and summer schools. TECHNICAL SUMMARYThis award supports research, education, and outreach activities with a goal to develop a theory and protocols for specific quantum algorithms, which may be implemented on commercial platforms, available through the NSF Cloud Bank. On the theory part, the qubit arrays represent examples of open dissipative quantum systems, which are driven by time-dependent local fields and couplings. Such a driven-dissipative environment can be modeled by the Lindbladian. The project will extend theoretical tools of non-equilibrium quantum field theory, to incorporate Lindbladian dynamics. One of the goals of this construction is to elucidate the existence and properties of the many-body localization transition in the Hilbert space of the array. Understanding of such transitions is crucial to developing protocols for the effective quantum cooling (i.e. approximate quantum optimization). Specifically, cooling of the glassy many-body localized phase may be achieved through periodic quantum melting through the first order transition and refreezing through the second order transition. The project will develop a theory of such dissipative cooling cycles and implement them on the D-Wave 5000-qubit platform. It will also develop tools for analyzing the resulting “experimental” data sets. The award also facilitates the PI's educational and outreach activities which contribute to the development of the US STEM workforce through development of quantum computation curriculum, preparing review articles, organization of workshops, and summer schools.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.