近日，法国中性原子量子计算公司Pasqal的Alexandre Dauphin及其研究团队取得一项新进展。经过不懈努力，他们对二维里德伯原子阵列中的非晶量子磁体进行研究。相关研究成果已于2024年7月1日在国际知名学术期刊《物理评论A》上发表。

在本文中，该研究团队建议用模拟量子模拟器来探索非晶量子磁体。为此，研究人员首先提出了一种算法来生成无定形量子磁体，适用于伊辛模型的里德伯模拟器。随后，研究人员使用半经典方法来初步了解模型的物理特性。特别是对于铁磁相互作用，研究人员计算了平均场相图，并利用线性自旋波理论研究了激励的局域化性质和动力结构因素。对于反铁磁相互作用，研究人员通过模拟退火证明了非晶磁体表现出复杂的经典能量景观。最后，他们概述了一个基于可编程镊子阵列中的里德伯原子的实验方案，从而为在难以经典模拟的情况下研究非晶量子磁体开辟了道路。

据悉，非晶固体，即具有明确的短程性质但缺乏长程有序的体系，是凝聚态物质中的一个重要研究课题。虽然它们的微观结构是已知的，这不同于它们的晶体对应物，关于非晶材料的涌现集体行为仍然有许多悬而未决的问题。在量子体系中尤其如此，在量子体系中，数值模拟极具挑战性。

附：英文原文

Title: Amorphous quantum magnets in a two-dimensional Rydberg atom array

Author: Sergi Julià-Farré, Joseph Vovrosh, Alexandre Dauphin

Issue&Volume: 2024/07/01

Abstract: Amorphous solids, i.e., systems which feature well-defined short-range properties but lack long-range order, constitute an important research topic in condensed matter. While their microscopic structure is known to differ from their crystalline counterpart, there are still many open questions concerning the emergent collective behavior in amorphous materials. This is particularly the case in the quantum regime, where the numerical simulations are extremely challenging. In this paper, we instead propose to explore amorphous quantum magnets with an analog quantum simulator. To this end, we first present an algorithm to generate amorphous quantum magnets, suitable for Rydberg simulators of the Ising model. Subsequently, we use semiclassical approaches to get a preliminary insight of the physics of the model. In particular, for ferromagnetic interactions, we calculate mean-field phase diagrams, and use the linear spin wave theory to study localization properties and dynamical structure factors of the excitations. For antiferromagnetic interactions, we show that amorphous magnets exhibit a complex classical energy landscape by means of simulated annealing. Finally, we outline an experimental proposal based on Rydberg atoms in programmable tweezer arrays, thus opening the road towards the study of amorphous quantum magnets in regimes difficult to simulate classically.

DOI: 10.1103/PhysRevA.110.012602

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.012602