Evidence for two separate energy gaps in underdoped high-temperature cuprate superconductors from broadband infrared ellipsometry.
Evidence for two separate energy gaps in underdoped high-temperature cuprate superconductors from broadband infrared ellipsometry.
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DOI：
10.1103/physrevlett.100.177004
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发表时间：
2008-05
影响因子：
8.6
通讯作者：
Li Yu;D. Munzar;A. Boris;P. Yordanov;J. Chaloupka;T. Wolf;C. Lin;B. Keimer;C. Bernhard
中科院分区：
文献类型：
--
作者：
Li Yu;D. Munzar;A. Boris;P. Yordanov;J. Chaloupka;T. Wolf;C. Lin;B. Keimer;C. Bernhard
我们用宽带红外椭偏仪测量了低掺杂的RBA2Cu3O7-Delta}(R=Y，ND，La)单晶的c轴电导率。我们的数据表明，由于正常态的赝隙和超导带隙，谱重的重新分布背后存在着独立的能量尺度。此外，它们提供了证据，表明这些能隙不共享相同的电子态，也不会在过度掺杂一侧合并。因此，我们的数据暗示了两个间隙的情况，其中的伪间隙很可能是超导电性的外在的。
We present broadband infrared ellipsometry measurements of the c-axis conductivity of underdoped RBa_{2}Cu_{3}O_{7-delta} (R=Y, Nd, and La) single crystals. Our data show that separate energy scales are underlying the redistributions of spectral weight due to the normal state pseudogap and the superconducting gap. Furthermore, they provide evidence that these gaps do not share the same electronic states and do not merge on the overdoped side. Accordingly, our data are suggestive of a two gap scenario with a pseudogap that is likely extrinsic with respect to superconductivity.