Excitonic insulator and novel trion states in twisted MoSe2/WSe2 bilayers

IF 2.4 4区物理与天体物理 Q3 PHYSICS, CONDENSED MATTER

Solid State Communications Pub Date : 2025-09-25 DOI:10.1016/j.ssc.2025.116164

Fenghua Qi , Jun Cao , Jie Cao , Xingfei Zhou , Guojun Jin

{"title":"Excitonic insulator and novel trion states in twisted MoSe2/WSe2 bilayers","authors":"Fenghua Qi , Jun Cao , Jie Cao , Xingfei Zhou , Guojun Jin","doi":"10.1016/j.ssc.2025.116164","DOIUrl":null,"url":null,"abstract":"<div><div>Twisted bilayer transition metal dichalcogenides have emerged as one of the most active research fields in recent years. At the full filling of the first moiré valence band, the electron–hole pairs formed in the moiré energy bands can combine to form moiré excitons. We investigate the phase diagram of twisted <span><math><mrow><msub><mrow><mtext>MoSe</mtext></mrow><mrow><mn>2</mn></mrow></msub><mo>/</mo><msub><mrow><mtext>WSe</mtext></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> bilayers with varying twist angle and moiré potential strength. It is found that a strong moiré potential is beneficial for the excitonic insulator (EI) state at large twist angles. Moreover, the condensation of moiré excitons can further induce a ground state with non-conserved trion number. The emergence of this state might provide novel electrical properties. A toy model is proposed to describe the occurrence of this state and a rigorous proof is given to the critical conditions through the application of the Feynman diagram technique.</div></div>","PeriodicalId":430,"journal":{"name":"Solid State Communications","volume":"405 ","pages":"Article 116164"},"PeriodicalIF":2.4000,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Solid State Communications","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0038109825003394","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}

引用次数: 0

Abstract

Twisted bilayer transition metal dichalcogenides have emerged as one of the most active research fields in recent years. At the full filling of the first moiré valence band, the electron–hole pairs formed in the moiré energy bands can combine to form moiré excitons. We investigate the phase diagram of twisted

{MoSe}_{2} / {WSe}_{2}

bilayers with varying twist angle and moiré potential strength. It is found that a strong moiré potential is beneficial for the excitonic insulator (EI) state at large twist angles. Moreover, the condensation of moiré excitons can further induce a ground state with non-conserved trion number. The emergence of this state might provide novel electrical properties. A toy model is proposed to describe the occurrence of this state and a rigorous proof is given to the critical conditions through the application of the Feynman diagram technique.

查看原文本刊更多论文

扭曲MoSe2/WSe2双分子层中的激子绝缘子和新三角态

双扭曲层过渡金属二硫族化合物是近年来最为活跃的研究领域之一。当第一个莫尔维尔价带填满时，莫尔维尔能带中形成的电子-空穴对可以结合形成莫尔维尔激子。我们研究了不同扭转角和莫尔势强度的扭曲MoSe2/WSe2双层膜的相图。研究发现，在大扭转角下，强莫尔势有利于激子绝缘体（EI）状态的形成。此外，莫尔激子的凝聚可以进一步诱导出具有非守恒三角数的基态。这种状态的出现可能会提供新的电学特性。提出了一个玩具模型来描述这种状态的发生，并应用费曼图技术对临界条件进行了严格的证明。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Solid State Communications 物理-物理：凝聚态物理

CiteScore

3.40

自引率

4.80%

发文量

287

审稿时长

51 days

期刊介绍： Solid State Communications is an international medium for the publication of short communications and original research articles on significant developments in condensed matter science, giving scientists immediate access to important, recently completed work. The journal publishes original experimental and theoretical research on the physical and chemical properties of solids and other condensed systems and also on their preparation. The submission of manuscripts reporting research on the basic physics of materials science and devices, as well as of state-of-the-art microstructures and nanostructures, is encouraged. A coherent quantitative treatment emphasizing new physics is expected rather than a simple accumulation of experimental data. Consistent with these aims, the short communications should be kept concise and short, usually not longer than six printed pages. The number of figures and tables should also be kept to a minimum. Solid State Communications now also welcomes original research articles without length restrictions. The Fast-Track section of Solid State Communications is the venue for very rapid publication of short communications on significant developments in condensed matter science. The goal is to offer the broad condensed matter community quick and immediate access to publish recently completed papers in research areas that are rapidly evolving and in which there are developments with great potential impact.