CAREER: Probing Quantum Matter using Programmable Quantum Simulators

最近在控制量子器件能力方面取得的进展，为研究由许多相互作用的粒子（如量子材料）组成的量子系统中出现的丰富而复杂的物理学提供了新的方法。一种很有前途的方法是量子模拟，其中一个具有几个可调参数的量子设备被仔细操纵以模拟各种其他感兴趣系统的物理特性。尽管前景光明，但目前的量子设备仍远未达到理想状态，因为它们的操作有噪声，控制它们的能力也不完善。核心挑战是(i)了解如何最佳地利用这些设备来探索最大的物理财富，尽管存在限制；（ii）从可能嘈杂和有限的数据中提取物理上有意义的信息。在这里，首席研究员建议通过利用量子信息科学和机器学习的最新进展，从理论上提出新的想法来解决这些挑战。首席研究员将在追求这一研究目标的同时，开展一系列推广活动，促进高中生和大学生的研究，吸引有才华的学生，并为他们成为下一代科学家做好准备。理解、控制和利用日益复杂的多体系统的量子动力学是量子科学研究的最重要目标之一。研究部分的前半部分旨在开发实现这些目标的实用方法，重点关注现有的实验能力。特别是，PI和他的团队将开发方法，通过优化脉冲控制来稳健地设计给定量子硬件的有效哈密顿量，并通过利用信息扰化来执行任意可观测值或非局部属性的高级测量。由于当前设备的量子控制的限制，这些能力在其他方面是困难的，需要新的理论思想。利用改进的能力，研究小组将继续探索奇异的突发现象，如使用现有的量子模拟器定义量子临界性。去定义量子临界性可能在理解高温超导体和其他量子材料方面发挥重要作用。利用量子模拟器成功地观察到奇异的突发现象，将允许对它们进行更详细的实验研究，加深我们对量子相和相变的理解。研究活动的后半部分介绍了用量子信息理论的语言研究量子物质的新视角。具体来说，研究团队将开发量子和经典算法，以有效地从实验数据中提取重要信息，如量子物质的相位，并研究这些新算法在计算能力方面的基本限制。这将提供表征量子物质特性的新方法，例如区分两种不同相的计算硬度。成功的结果将在物理科学的不同学科之间建立严格的联系，如理论物理中的重整化群和误差校正信息理论。该奖项由数学和物理科学理事会内的材料研究部和物理部共同提供资金支持。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 SUMMARYRecent advances in the ability to control quantum devices are ushering in new approaches to study the rich and complex physics that emerges from quantum systems of many interacting particles such as quantum materials. One promising approach is quantum simulation, in which a quantum device with several tunable parameters is carefully manipulated to emulate the physics of various other systems of interest. Despite their promise, present-day quantum devices are still far from ideal, as their operations are noisy and the ability to control them is imperfect. The central challenges are (i) to understand how to optimally exploit such devices to explore the largest wealth of physics possible despite the restrictions and (ii) to extract physically meaningful information from potentially noisy and limited data. Here, the principal investigator proposes to address these challenges through novel ideas from theory leveraging recent advances in quantum information science and machine learning. The principal investigator will pursue this research goal in parallel with a diverse set of outreach activities fostering high-school and undergraduate student research, attracting talented students, and preparing them as the next generation scientists.TECHNICAL SUMMARYUnderstanding, controlling, and harnessing the quantum dynamics of increasingly complex many-body systems are among the most important goals of quantum science research. The first half of the research component aims to develop practical methods to achieve these goals, focusing on existing experimental capabilities. In particular, the PI and his team will develop methods to robustly engineer effective Hamiltonians of a given quantum hardware by means of optimized pulsed controls and to perform advanced measurements of arbitrary observables or nonlocal properties by utilizing information scrambling. These capabilities are otherwise difficult owing to limitations in quantum control of current devices, calling for novel theory ideas. Leveraging improved capabilities, the research team will pursue probing exotic emergent phenomena such as deconfined quantum criticality using existing quantum simulators. Deconfined quantum criticality may plan an important role in understanding high temperature superconductors and other quantum materials. Successful observations of exotic emergent phenomena using quantum simulators will allow the experimental investigations of them in greater detail, deepening our understanding of quantum phases and phase transitions. The second half of the research activities introduces a new perspective to study quantum matter using the language of quantum information theory. Specifically, the research team will develop quantum and classical algorithms to efficiently extract important information such as the phase of quantum matter from experimental data and investigate the fundamental limitations in computational power of these new algorithms. This will provide new ways to characterize the properties of quantum matter such as the computational hardness of distinguishing two different phases. Successful outcomes will establish a rigorous connection between different disciplines of physical sciences such as renormalization group in theoretical physics and error corrections information theory.This award is jointly supported through funds contributed by the Division of Materials Research and the Physics Division within the Mathematical and Physical Sciences Directorate.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.