Formation of the excitonic insulator state in Ta2NiSe5

Ta2NiSe5 中激子绝缘体态的形成

• 批准号: 433553211
• 负责人: Dr. Satoshi Ejima
• 金额: --
• 依托单位: Max-Planck-Institut für Festkörperforschung (MPI-FKF)
• 依托单位国家: 德国
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/433553211?language=en
• 关键词: Formation; excitonic; insulator; state; Ta2NiSe5

More than half a century ago, theory predicts that electrons and holes will pair in proximity to a semiconductor-semimetal transition and even may form a macroscopically quantum coherent state at low temperatures, the so-called excitonic insulator (EI). But only recently there has been strong experimental evidence for such an equilibrium condensation phenomenon in a bulk material, mainly in systems with reduced electronic dimension. The most promising compound in this respect is quasi-one-dimensional (1D) Ta_2NiSe_5 (TNS), where the distinct flattening of the valence-band top observed in the angle-resolved photoemission spectroscopy below the structural transition temperature (T

半个多世纪以前，理论预测电子和空穴将在半导体-半金属跃迁附近配对，甚至可能在低温下形成宏观量子相干态，即所谓的激子绝缘体（EI）。但直到最近才有强有力的实验证据证明这种平衡凝聚现象在块状材料中，主要是在电子尺寸减小的系统中。在这方面最有希望的化合物是准一维（1D） Ta_2NiSe_5 (TNS)，在角度分辨光谱学中，在结构转变温度(T)以下，价带顶部明显变平