Excitonic Bose-Einstein condensation in Ta2NiSe5 above room temperature
Excitonic Bose-Einstein condensation in Ta2NiSe5 above room temperature
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DOI：
10.1103/physrevb.90.155116
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发表时间：
2014-10-13
影响因子：
3.7
通讯作者：
Ohta, Y.
中科院分区：
文献类型：
--
作者：
Seki, K.;Wakisaka, Y.;Ohta, Y.
我们表明，有限温度变分集团近似（VCA）计算的扩展Falicov-Kimball模型可以重现角分辨光电子能谱（ARPES）的结果在Ta 2NiSe 5跨越半导体结构相变在325 K。我们证明，只有当考虑到强激子涨落时，才能通过激子绝缘体的实际模型上的VCA计算再现由ARPES观察到的平顶价带的特征温度依赖性。计算结果表明，Ta_2NiSe_5福尔斯处于玻色-爱因斯坦凝聚态.
We show that finite temperature variational cluster approximation (VCA) calculations on an extended Falicov-Kimball model can reproduce angle-resolved photoemission spectroscopy (ARPES) results on Ta2NiSe5 across a semiconductor-to-semiconductor structural phase transition at 325 K. We demonstrate that the characteristic temperature dependence of the flat-top valence band observed by ARPES is reproduced by the VCA calculation on the realistic model for an excitonic insulator only when the strong excitonic fluctuation is taken into account. The present calculations indicate that Ta2NiSe5 falls in the Bose-Einstein condensation regime of the excitonic insulator state.