过渡金属碳化物（MXenes）的鲁棒高温拓扑激子绝缘体
Robust high-temperature topological excitonic insulator of transition-metal carbides (MXenes)
AI总结：
本文提出“宇称阻挫”机制解释拓扑激子绝缘体罕见的原因，并通过第一性原理计算证明单层MXenes可实现室温鲁棒拓扑激子凝聚，为寻找新材料和探究拓扑与多体效应相互作用提供了新平台。
摘要：
拓扑激子绝缘体结合了拓扑边缘态和自发激子凝聚，具有拓扑绝缘体和激子绝缘体的双重功能。然而，它们非常罕见，人们对其形成机制知之甚少。在这项工作中，我们发现一种被称为“宇称阻挫”的机制阻止了通常拓扑绝缘体中的激子不稳定性，而那些能带反转不依赖于自旋-轨道耦合的体系是可能的候选者。我们通过对单层过渡金属碳化物（MXenes）的第一性原理计算验证了这一点，计算表明其存在鲁棒的热平衡激子凝聚，足以在室温下用于拓扑应用。这种状态可以通过角分辨光电子能谱和输运测量来识别。我们的工作不仅为寻找更多拓扑激子绝缘体提供了指导，也为研究非平庸能带拓扑与量子多体效应之间的相互作用提供了一个新平台。
英文摘要：
Topological excitonic insulators combine topological edge states and spontaneous exciton condensation, with dual functionality of topological insulators and excitonic insulators. Yet, they are very rare and little is known about their formation. In this work, we find that a mechanism dubbed as parity frustration prevents excitonic instability in usual topological insulators, and those whose band inversion is independent of spin-orbit coupling are possible candidates. We verify this by first-principles calculations on monolayer transition-metal carbides (MXenes), which show a robust thermal-equilibrium exciton condensation, being sufficient for topological applications at room temperature. Such a state can be identified by angle-resolved photoemission spectroscopy and transport measurement. Our work provides not only a guide for finding more topological excitonic insulators, but also a new platform for studying the interplay between non-trivial band topology and quantum many-body effects.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
