Unusual electronic state of Sn in AgSnSe2
Unusual electronic state of Sn in AgSnSe2
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AgSnSe2 中 Sn 的异常电子态
DOI：
10.1103/physrevb.101.075134
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发表时间：
2020
影响因子：
3.7
通讯作者：
Akimitsu J.
中科院分区：
文献类型：
--
作者：
Naijo Y.;Hada K.;Furukawa T.;Itou T.;Ueno T.;Kobayashi K.;Mazin I. I.;Jeschke H. O.;Akimitsu J.
根据形式电子计数，Sn的价态应该是非常不寻常的，因此认为Sn是一种具有负中心和局部电子配对潜力的跳价化合物。有人提出，后者可能是该化合物中超越看似传统的超导性的机制。我们报告的核磁共振测量和第一原理计算，彼此完全一致，都表明，跳价没有发生，而实现了非常不寻常的状态，可能是因为几何约束禁止呼吸扭曲，可以屏蔽现场库仑排斥。
, by formal electron count, should have Sn in a highly unusualvalence state and was therefore suggested to be a valence-skipping compound with potential for negative-centers and local electron pairing. It has been proposed that the latter may be the mechanism beyond seemingly conventional superconductivity in this compound. We report NMR measurements and first-principles calculations that agree with each other perfectly, and both indicate that valence skipping does not take place and the highly unusualstate is realized instead, likely because of geometrical constraint prohibiting a breathing distortion that could screen the on-site Coulomb repulsion.