Collaborative Research: Advances in Quantum Control and Noise Mitigation on A Highly Accurate Testbed

量子技术利用量子力学的全部力量来处理信息，其处理方式甚至超过了最强大的经典超级计算机的能力。据设想，这种机器将推动高科技材料和制药的发展，以及高能和凝聚态物理等领域的基础研究的发展。虽然通用量子计算机还需要数年的时间，但量子硬件的稳步发展将我们带入了嘈杂的中间尺度量子(NISQ)设备时代。这个时代的关键挑战是驯服阻碍这些设备性能的错误和缺陷，使它们能够发展出必要的复杂性，以实现相对于经典设备的量子优势。这个项目寻求开发和测试新的技术来控制这些设备并使它们免受噪音的影响，并更好地了解它们的基本限制。这样的理解对于加速量子技术在科学和工程问题上的应用是至关重要的。拟议的项目是一个包括实验和理论部分的合作努力。它的主要目标是开发和测试量子处理器中的量子控制和噪声缓解的新技术，并着眼于未来在NISQ模拟器中的应用。出于测试目的，该小组将使用一个小型的、高精度的量子(Shaq)处理器，该处理器基于单个铯原子的内部自旋态。通过量子最优控制，Shaq处理器可以在中等大小但不平凡的16维希尔伯特空间中进行普遍编程，允许访问任意状态准备、酉图和任何基础上的测量。计划中的升级将提高量子模拟的准确性和持续时间，可以执行到最先进的水平。这将它定位为一个理想的真实世界实验试验台，可以直接与理论模型进行比较。主要研究项目将包括深量子电路和Floquet系统的模拟，量子混沌和动力学不稳定性在错误扩散中所起作用的研究，噪声定制和量子误差缓解的技术，以及Floquet时间晶体的理论和实验研究。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Quantum technologies use the full power of quantum mechanics to process information in ways that go beyond the capabilities of even the most powerful classical supercomputers. It is envisioned that such machines would propel development of both high tech materials and pharmaceuticals, and also of basic research in areas like high energy and condensed matter physics. While general purpose quantum computers are still years in the future, steady development in quantum hardware have brought us to the era of Noisy Intermediate Scale Quantum (NISQ) devices. The key challenge in this era is to tame the errors and imperfections hindering the performance of these devices to allow them to develop the necessary complexity to achieve quantum advantage over their classical counterparts. This project seeks to develop and test new techniques to both control these devices and to shield them from noise, and to better understand their fundamental limitations. Such understanding is essential to accelerate the application of quantum technologies to problems in science and engineering.The proposed project is a collaborative effort with both experimental and theoretical components. Its main goal is to develop and test new techniques for quantum control and noise mitigation in quantum processors, with an eye to future applications in NISQ simulators. For testing purposes, the group will employ a Small, Highly Accurate Quantum (SHAQ) processor based on the internal spin states of individual cesium atoms. By way of quantum optimal control, the SHAQ processor is universally programmable in a moderately-sized but nontrivial 16-dimensional Hilbert space, allowing access to arbitrary state preparations, unitary maps, and measurements in any basis. A planned upgrade will increase both the accuracy and duration of quantum simulations that can be performed to state-of-the art levels. This positions it as an ideal real-world experimental testbed that can be compared directly against theoretical models. Key research thrusts will include the simulation of deep quantum circuits and Floquet systems, studies of the role played by quantum chaos and dynamical instability in the proliferation of errors, techniques for noise tailoring and quantum error mitigation, and studies of Floquet Time Crystals in both theory and experiment.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.