近日，北京大学的林熙及其研究团队取得一项新进展。经过不懈努力，他们揭示表面声波与量子霍尔效应的相互作用。相关研究成果已于2024年4月1日在国际知名学术期刊《中国物理快报》上发表。

据悉，表面声波(SAW)是研究二维电子系统中量子相的一种强有力的技术。电子对SAW压电场的响应是通过屏蔽、振幅衰减和速度移动来实现的，这一过程可以用弛豫模型来描述。

在这项工作中，研究人员系统地研究了这种相互作用，使用比以前的研究低几个数量级的声呐振幅。在高磁场环境中，研究人员观察到，当电子形成高度关联态（如量子霍尔效应）时，声呐出现了异常的大幅衰减现象，而声速却依然保持在较高水平，这与传统的弛豫模型存在显著的不符。值得注意的是，这种异常现象仅在SAW功率足够低的情况下出现。

附：英文原文

Title: Interaction between Surface Acoustic Wave and Quantum Hall Effects

Author:Xiao Liu¹, Mengmeng Wu¹, Renfei Wang¹, Xinghao Wang¹, Wenfeng Zhang¹, Yujiang Dong¹, Rui-Rui Du^1,2, Yang Liu^1,3*, and Xi Lin^1,3,4*

Issue&Volume: 2024-04-01

Abstract: Surface acoustic wave (SAW) is a powerful technique for investigating quantum phases appearing in two-dimensional electron systems. The electrons respond to the piezoelectric field of SAW through screening, attenuating its amplitude, and shifting its velocity, which is described by the relaxation model. In this work, we systematically study this interaction using orders of magnitude lower SAW amplitude than those in previous studies. At high magnetic fields, when electrons form highly correlated states such as the quantum Hall effect, we observe an anomalously large attenuation of SAW, while the acoustic speed remains considerably high, inconsistent with the conventional relaxation model. This anomaly exists only when the SAW power is sufficiently low.

DOI: 10.1088/0256-307X/41/4/047301

Source: https://cpl.iphy.ac.cn/10.1088/0256-307X/41/4/047301