近日，美国哈佛大学的Markus Greiner及其研究团队取得一项新进展。经过不懈努力，他们发现在哈伯德量子模拟器中出现的偶极量子固体。相关研究成果已于2023年10月25日在国际权威学术期刊《自然》上发表。

本文利用超冷磁性铒原子，在具有长程偶极相互作用的强关联晶格系统中实现了新的量子相。研究人员通过调整偶极相互作用成为系统中的主要能量尺度，观察到从超流体到偶极量子固体的量子相变，并使用带手风琴晶格的量子气体显微镜直接检测到这一点。通过控制偶极子的取向，他们实现了多种条纹有序态，展现出相互作用的各向异性。此外，研究人员还通过非绝热跃迁观察到一系列亚稳条纹有序态的出现。这项工作表明，利用光学晶格中的长程偶极相互作用可以实现新的强关联量子相，为量子模拟具有长程和各向异性相互作用的广泛晶格模型提供了可能。

据悉，在量子力学多体系统中，长程和各向异性相互作用能够促进丰富的空间结构，并可能导致量子阻挫，从而产生大量复杂的、强关联的量子相。这种相互作用在自然界中发挥着重要作用。然而，目前晶格系统的量子模拟在很大程度上无法实现这种相互作用。为了探索长程相互作用晶格系统，科学家们正在利用极性分子、里德伯原子、光学空腔或磁性原子等实验手段进行尝试。

附：英文原文

Title: Dipolar quantum solids emerging in a Hubbard quantum simulator

Author: Su, Lin, Douglas, Alexander, Szurek, Michal, Groth, Robin, Ozturk, S. Furkan, Krahn, Aaron, Hbert, Anne H., Phelps, Gregory A., Ebadi, Sepehr, Dickerson, Susannah, Ferlaino, Francesca, Markovi, Ognjen, Greiner, Markus

Issue&Volume: 2023-10-25

Abstract: In quantum mechanical many-body systems, long-range and anisotropic interactions promote rich spatial structure and can lead to quantum frustration, giving rise to a wealth of complex, strongly correlated quantum phases. Long-range interactions play an important role in nature; however, quantum simulations of lattice systems have largely not been able to realize such interactions. A wide range of efforts are underway to explore long-range interacting lattice systems using polar molecules, Rydberg atoms, optical cavities or magnetic atoms. Here we realize novel quantum phases in a strongly correlated lattice system with long-range dipolar interactions using ultracold magnetic erbium atoms. As we tune the dipolar interaction to be the dominant energy scale in our system, we observe quantum phase transitions from a superfluid into dipolar quantum solids, which we directly detect using quantum gas microscopy with accordion lattices. Controlling the interaction anisotropy by orienting the dipoles enables us to realize a variety of stripe-ordered states. Furthermore, by transitioning non-adiabatically through the strongly correlated regime, we observe the emergence of a range of metastable stripe-ordered states. This work demonstrates that novel strongly correlated quantum phases can be realized using long-range dipolar interactions in optical lattices, opening the door to quantum simulations of a wide range of lattice models with long-range and anisotropic interactions.

DOI: 10.1038/s41586-023-06614-3

Source: https://www.nature.com/articles/s41586-023-06614-3