近日，奥地利因斯布鲁克大学Ringbauer, Martin团队实现了在量子计算机上模拟二维晶格规范理论。2025年3月25日出版的《自然—物理学》杂志发表了这项成果。
粒子物理学通过规范理论描述了物质和力的相互作用。然而，规范理论的内在量子性质使得经典计算技术难以解决重要问题。量子计算机为克服这些障碍提供了一种有前景的方法。研究组证明了这条路径上的两个基本要求：首先，对二维晶格量子电动力学的基本构建块的性质进行量子计算，涉及规范场和物质。其次，展示了如何使用捕获离子量子处理器将规范场离散化细化到最小表示之外，其中量子信息以每个离子的几个状态编码。
这样的qudits非常适合描述规范场，规范场自然是高维的，从而减小了寄存器大小和电路复杂性。研究组使用变分量子本征求解器准备模型的基态，并观察动态物质对量子化磁场的影响。通过控制量子维数，还展示了如何无缝观察不同规范场截断的效果。最后，还通过实验研究了成对产生和磁能的动力学。该结果为在近期量子器件中使用qudits对规范理论进行硬件高效的量子模拟打开了大门。
附：英文原文
Title: Simulating two-dimensional lattice gauge theories on a qudit quantum computer
Author: Meth, Michael, Zhang, Jinglei, Haase, Jan F., Edmunds, Claire, Postler, Lukas, Jena, Andrew J., Steiner, Alex, Dellantonio, Luca, Blatt, Rainer, Zoller, Peter, Monz, Thomas, Schindler, Philipp, Muschik, Christine, Ringbauer, Martin
Issue&Volume: 2025-03-25
Abstract: Particle physics describes the interplay of matter and forces through gauge theories. Yet, the intrinsic quantum nature of gauge theories makes important problems notoriously difficult for classical computational techniques. Quantum computers offer a promising way to overcome these roadblocks. We demonstrate two essential requirements on this path: first, we perform a quantum computation of the properties of the basic building block of two-dimensional lattice quantum electrodynamics, involving both gauge fields and matter. Second, we show how to refine the gauge-field discretization beyond its minimal representation, using a trapped-ion qudit quantum processor, where quantum information is encoded in several states per ion. Such qudits are ideally suited for describing gauge fields, which are naturally high dimensional, leading to reduced register size and circuit complexity. We prepare the ground state of the model using a variational quantum eigensolver and observe the effect of dynamical matter on quantized magnetic fields. By controlling the qudit dimension, we also show how to seamlessly observe the effect of different gauge-field truncations. Finally, we experimentally study the dynamics of pair creation and magnetic energy. Our results open the door for hardware-efficient quantum simulations of gauge theories with qudits in near-term quantum devices.
DOI: 10.1038/s41567-025-02797-w
Source: https://www.nature.com/articles/s41567-025-02797-w