Manipulating Spinor Quantum Gases --- Spin, Charge and Their Interplay

了解量子材料对于发展新兴的量子技术至关重要。许多量子材料属于量子多体系统，它是由相互作用的量子粒子组成的。这里的挑战在于，量子多体系统的研究总体上是极其困难的。这项拟议的研究利用冷原子的平台来解决这个具有挑战性的问题-在气相的真空室中隔离的原子，冷却到极低的温度，使它们的行为受到量子力学规则的支配。这些冷原子系统可以进行精细的实验控制，它们的微观相互作用通常是很好地理解的。因此，对冷原子的研究通常可以为一般量子多体系统提供新的基本见解。因此，提出的研究将促进科学的进步。通过学生参与研究，该提案还将支持一系列STEM领域的教育和技术培训。更具体地说，这项拟议的研究建立在该小组过去的成功基础上，涉及旋量量子气体的研究，重点是自旋和电荷自由度之间的相互作用。这项研究围绕三个主题展开：一维旋量量子气体中自旋-电荷分离的研究；使用旋量凝聚对晶格规范理论和狄拉克弦的量子模拟；超越二能级原子范式的广义Dicke模型中多结性的研究。为了解决这些问题，将使用和开发广泛的分析和数值工具。这些项目既解决了长期存在的挑战(例如，探测和表征一维奇异量子现象，如自旋-电荷分离和自旋非相干Luttinger液体)，也解决了新的发展(例如，开发新方法来研究强相互作用极限下的一维晶格模型，建立一个系统研究多临界现象的理论平台)。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。

Understanding quantum materials is essential for developing emerging quantum technology. Many of the quantum materials belong to the class of quantum many-body systems, which consist of quantum particles interacting with each other. The challenge here lies in the fact that the study of quantum many-body systems is in general extremely difficult. The proposed research tackles this challenging problem using the platform of cold atoms --- atoms isolated in vacuum chambers in the gaseous phase and cooled down to extremely low temperature such that their behavior is governed by the rules of quantum mechanics. These cold atomic systems are amenable to exquisite experimental control and their microscopic interactions are often well understood. As such, the study of cold atoms can often provide new fundamental insights into general quantum many-body systems. Therefore, the proposed research will promote the progress of science. Through student involvement in the research, this proposal will also support education and technical training in a spectrum of STEM fields. More specifically, the proposed research builds upon the group's past success and involves the study of spinor quantum gases, focusing on the interplay between the spin and the charge degrees of freedom. The research is organized around three themes: study of spin-charge separation in one-dimensional spinor quantum gases; quantum simulation of lattice gauge theory and Dirac string using spinor condensates; study of multicriticality in generalized Dicke models beyond the two-level atom paradigm. To tackle these problems, a wide spectrum of analytical and numerical tools will be employed and developed. The projects addresses both long-standing challenges (for example, the detection and characterization of exotic quantum phenomena in one dimension such as spin-charge separation and spin-incoherent Luttinger liquid), and new developments (for example, developing new methods to study 1D lattice models in strong interaction limit, building a theoretical platform to systematically study multicritical phenomena).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.