Change of carrier density at the pseudogap critical point of a cuprate superconductor
Change of carrier density at the pseudogap critical point of a cuprate superconductor
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DOI：
10.1038/nature16983
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发表时间：
2016-03-10
期刊：
影响因子：
64.8
通讯作者：
Proust, Cyril
中科院分区：
文献类型：
--
作者：
Badoux, S.;Tabis, W.;Proust, Cyril
赝能隙是电子态密度中的部分能隙，在铜酸盐超导体的正常（非超导）状态下打开，其起源是一个长期存在的谜团。它与低掺杂（空穴浓度，p）下的莫特绝缘体相的联系仍然不明确(1)，并且其与在中等掺杂下重建费米表面(5,6)的电荷顺序(2-4)的关系仍不清楚(7-10)。在这里，我们使用高达 88 特斯拉的磁场中的霍尔系数测量来表明，铜酸盐 YBa2Cu3Oy 中按电荷顺序进行的费米表面重建在临界掺杂 p = 0.16 处急剧结束，明显低于赝能隙临界点 p* = 0.19（参考文献 11）。这表明赝能隙和电荷顺序是不同的现象。我们发现，载流子密度 n 从高掺杂（参考文献 12）的传统金属中的 n = 1 + p 到低掺杂（参考文献 13）的 n = p 的变化始于赝能隙临界点。这表明赝能隙和反铁磁莫特绝缘体是相关的。
The pseudogap is a partial gap in the electronic density of states that opens in the normal (non-superconducting) state of cuprate superconductors and whose origin is a long-standing puzzle. Its connection to the Mott insulator phase at low doping (hole concentration, p) remains ambiguous(1) and its relation to the charge order(2-4) that reconstructs the Fermi surface(5,6) at intermediate doping is still unclear(7-10). Here we use measurements of the Hall coefficient in magnetic fields up to 88 tesla to show that Fermisurface reconstruction by charge order in the cuprate YBa2Cu3Oy ends sharply at a critical doping p = 0.16 that is distinctly lower than the pseudogap critical point p* = 0.19 (ref. 11). This shows that the pseudogap and charge order are separate phenomena. We find that the change in carrier density n from n = 1 + p in the conventional metal at high doping (ref. 12) to n = p at low doping (ref. 13) starts at the pseudogap critical point. This shows that the pseudogap and the antiferromagnetic Mott insulator are linked.