Simulating Quantum Spin Models with Laser-Cooled Molecules in Optical Tweezer Arrays

量子力学在许多物理学问题中扮演着核心角色，从黑洞的行为到磁铁存在的原因。尽管孤立的单个粒子的量子力学被很好地理解，并导致了各种各样的现代技术，如激光和原子钟，但相互作用的量子粒子系统却没有被很好地理解。这样的系统提供了有趣的可能性，比如表现出超导性或形成量子计算机的基础，但相互作用的量子系统的特性很难预测，在许多情况下超出了最强大的计算机的能力。为了应对这一挑战，研究小组将建立一个新的“量子模拟器”，该模拟器基于聚焦激光束保持超冷温度下的分子。该平台将利用分子固有的量子相互作用来探索各种相互作用的量子模型。这些探索不仅可以提高我们对复杂量子系统的理解，而且可能为新型量子材料和量子增强传感器等实际应用提供新的见解。此外，该研究通过对研究生和本科生的培养产生了直接的社会影响。随着社会对量子科学及其前景的日益关注，这项研究工作将有助于在工业、国家实验室和学术界建立一支懂量子的劳动力队伍。相互作用的量子自旋模型与物理学的许多不同领域有着深刻的联系。各种自旋模型可以捕捉真实材料的磁性行为，甚至可以模拟黑洞的特性。研究大规模自旋系统的一个关键挑战是预测它们产生的量子动力学，这通常超出了最先进的理论所能达到的范围。虽然一些自旋模型可以利用现有的基于中性原子和离子的量子平台进行实验探索，但可访问模型的种类有限。为了解决这一限制，研究小组将开发一种新型量子模拟器，利用两种新兴技术，激光冷却分子和可编程光镊子陷阱阵列。通过将量子自旋映射到分子的量子旋转，并利用分子之间固有的电偶极相互作用，基于分子的量子模拟器可以在中等大小的阵列中提供各种远程相互作用自旋模型。具体来说，该团队将1)开发新的基于分子的量子模拟器的必要构建块，其中包括开发初始化和检测大型分子阵列的方法；2)在一维分子阵列中创建并验证有效的远程自旋-自旋相互作用。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。

Quantum mechanics plays a central role in many questions in physics ranging from how blackholes behave to why magnets exist. Although the quantum mechanics of isolated single particles is well-understood and has led to a wide variety of modern-day technologies such as lasers and atomic clocks, systems of interacting quantum particles are not nearly as well-understood. Such systems offer interesting possibilities such as exhibiting superconductivity or forming the basis of quantum computers, but the properties of interacting quantum systems are difficult to predict and in many cases are beyond the capabilities of the most powerful computers. To address this challenge, the research team will build a novel “quantum simulator” based on molecules at ultracold temperatures held by focused laser beams. The platform will harness quantum interactions inherent to molecules to explore a variety of interacting quantum models. These explorations could not only improve our understanding of complex quantum systems, but potentially provide new insight for practical applications such as novel quantum materials and quantum-enhanced sensors. In addition, the research has direct societal impact through the training of graduate and undergraduate students. With the ever-growing societal focus on quantum science and its promises, the research effort will contribute to building a quantum-literate workforce in industry, national labs and academia.Models of interacting quantum spins have deep connections to many diverse areas of physics. Various spin models can capture the magnetic behavior of real-life materials or even mimic properties of blackholes. A key challenge in studying large-scale spin systems is predicting their resulting quantum dynamics, which is often beyond the reach of state-of-the-art theory. While some spin models can be experimentally explored using existing quantum platforms based on neutral atoms and ions, the variety of accessible models is limited. To address this limitation, the research team will develop a novel quantum simulator leveraging two nascent technologies, laser-cooled molecules and programmable arrays of optical tweezer traps. By mapping quantum spins to the quantum rotations of molecules, and using the inherent electric dipolar interactions between molecules, the molecule-based quantum simulator could provide access to a variety of long-ranged interacting spin models in intermediate-sized arrays. Specifically, the team will 1) develop the necessary building blocks of the new molecule-based quantum simulator, which include developing methods to initialize and detect large arrays of molecules; and 2) create and verify effective long-range spin-spin interactions in 1D molecular arrays.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.