Ultrafast mid-infrared response of YRa2Cu3O7-δ
Ultrafast mid-infrared response of YRa2Cu3O7-δ
复制标题
DOI：
10.1126/science.287.5452.470
复制
发表时间：
2000-01-21
期刊：
影响因子：
56.9
通讯作者：
Walmsley, DG
中科院分区：
文献类型：
--
作者：
Kaindl, RA;Woerner, M;Walmsley, DG
高转变温度超导体的中红外光谱显示出面内导电性的缺口，其对超导性的作用仍然没有得到解决。飞秒测量的中红外反射率的YBa 2Cu 3 O 7-δ非平衡光激发后，用于证明超快填充这个间隙，并揭示了两个间隙成分：皮秒恢复的超导冷凝物在欠掺杂和最佳掺杂的材料，在欠掺杂的YBa 2Cu 3 O 7-δ，一个额外的亚皮秒组件有关的赝能隙相关性。这两个贡献的温度相关的振幅与反铁磁41毫电子伏特峰值中子散射，支持电荷和自旋激发之间的耦合。
Optical spectra of high-transition-temperature superconductors in the midinfrared display a gap of in-plane conductivity whose role for superconductivity remains unresolved. Femtosecond measurements of the mid-infrared reflectivity of YBa2Cu3O7-delta after nonequilibrium optical excitation are used to demonstrate the ultrafast fill-in of this gap and reveal two gap constituents: a picosecond recovery of the superconducting condensate in underdoped and optimally doped material and, in underdoped YBa2Cu3O7-delta, an additional subpicosecond component related to pseudogap correlations. The temperature-dependent amplitudes of both contributions correlate with the antiferromagnetic 41-millielectronvolt peak in neutron scattering, supporting the coupling between charges and spin excitations.