Bo Chen, Jian Liu, Lin Xue, Zhi Yang, Yong-Jia Zhang
{"title":"Two-dimensional valley-layer coupling heterostructures","authors":"Bo Chen, Jian Liu, Lin Xue, Zhi Yang, Yong-Jia Zhang","doi":"10.1063/5.0254488","DOIUrl":null,"url":null,"abstract":"Coupling valleys with different layers is a feasible way to realize valley polarization through a gate electric field, but only a few two-dimensional (2D) materials with locked valley and layer physics have been found so far. In this Letter, we show that valley-layer coupling (VLC), which is robust against spin–orbit coupling, could be achieved in 2D heterostructures built using distinct 2D monolayers with no VLC feature, as demonstrated by density functional theory calculations on Tl3Cl3/Ba2I2F2/Tl3Cl3 and Sn2Te2/K2Br2/Sn2Te2 van der Waals heterostructures. These two heterostructures exhibit valley-selective linear dichroism, which enables the optical creation of interlayer or intralayer excitons with selected valley and electric polarization. Furthermore, both the K2Br2/Sn2Te2/K2Br2 and Sn2Te2/K2ClBr/Sn2Te2 heterostructures are ferrovalley materials due to the ferroelectricity of Sn2Te2 and the built-in electric field caused by Janus K2ClBr, respectively. Our results broaden the candidate VLC materials from 2D monolayers and bilayers to 2D van der Waals heterostructures.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"22 1","pages":""},"PeriodicalIF":3.6000,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Physics Letters","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1063/5.0254488","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, APPLIED","Score":null,"Total":0}
引用次数: 0
Abstract
Coupling valleys with different layers is a feasible way to realize valley polarization through a gate electric field, but only a few two-dimensional (2D) materials with locked valley and layer physics have been found so far. In this Letter, we show that valley-layer coupling (VLC), which is robust against spin–orbit coupling, could be achieved in 2D heterostructures built using distinct 2D monolayers with no VLC feature, as demonstrated by density functional theory calculations on Tl3Cl3/Ba2I2F2/Tl3Cl3 and Sn2Te2/K2Br2/Sn2Te2 van der Waals heterostructures. These two heterostructures exhibit valley-selective linear dichroism, which enables the optical creation of interlayer or intralayer excitons with selected valley and electric polarization. Furthermore, both the K2Br2/Sn2Te2/K2Br2 and Sn2Te2/K2ClBr/Sn2Te2 heterostructures are ferrovalley materials due to the ferroelectricity of Sn2Te2 and the built-in electric field caused by Janus K2ClBr, respectively. Our results broaden the candidate VLC materials from 2D monolayers and bilayers to 2D van der Waals heterostructures.
不同层间耦合谷是利用栅极电场实现谷极化的一种可行方法，但目前发现的具有锁谷和层物理特性的二维材料很少。本文通过对Tl3Cl3/Ba2I2F2/Tl3Cl3和Sn2Te2/K2Br2/Sn2Te2 van der Waals异质结构的密度泛函理论计算，证明了谷层耦合（VLC）对自旋轨道耦合具有鲁强性，可以在使用不同的二维单层构建的二维异质结构中实现。这两种异质结构表现出谷选择性线性二色性，这使得具有选择谷和电极化的层间或层内激子的光学产生成为可能。此外，K2Br2/Sn2Te2/K2Br2和Sn2Te2/K2ClBr/Sn2Te2异质结构都是铁谷材料，分别是由于Sn2Te2的铁电性和Janus K2ClBr引起的内嵌电场。我们的研究结果将候选VLC材料从二维单层和双层扩展到二维范德华异质结构。
期刊介绍：
Applied Physics Letters (APL) features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, APL offers prompt publication of new experimental and theoretical papers reporting applications of physics phenomena to all branches of science, engineering, and modern technology.
In addition to regular articles, the journal also publishes invited Fast Track, Perspectives, and in-depth Editorials which report on cutting-edge areas in applied physics.
APL Perspectives are forward-looking invited letters which highlight recent developments or discoveries. Emphasis is placed on very recent developments, potentially disruptive technologies, open questions and possible solutions. They also include a mini-roadmap detailing where the community should direct efforts in order for the phenomena to be viable for application and the challenges associated with meeting that performance threshold. Perspectives are characterized by personal viewpoints and opinions of recognized experts in the field.
Fast Track articles are invited original research articles that report results that are particularly novel and important or provide a significant advancement in an emerging field. Because of the urgency and scientific importance of the work, the peer review process is accelerated. If, during the review process, it becomes apparent that the paper does not meet the Fast Track criterion, it is returned to a normal track.
京公网安备 11010802042870号
京ICP备2023020795号-1
分享
求助内容：
应助结果提醒方式：
扫码关注我们
