Tunneling spectroscopy study of spin-polarized quasiparticle injection effects in cuprate/manganite heterostructures
Tunneling spectroscopy study of spin-polarized quasiparticle injection effects in cuprate/manganite heterostructures
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铜酸盐/锰酸盐异质结构中自旋极化准粒子注入效应的隧道光谱研究
DOI：
10.1063/1.370249
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发表时间：
1999
影响因子：
3.2
通讯作者：
R. Vasquez
中科院分区：
文献类型：
--
作者：
J. Wei;N. Yeh;C. Fu;R. Vasquez
在 4.2 K 下对包含 YBa2Cu3O7−δ 和 La0.7Ca0.3MnO3 的外延薄膜异质结构进行扫描隧道光谱，以研究半金属铁磁锰酸盐自旋极化准粒子注入对高 Tc 铜酸盐超导体的微观效应。观察到的准粒子隧道特性与 d 波配对对称性一致，最大间隙 Δ0≈22 meV，注入电流至少为 35 mA (7×103 A/cm2)。尽管原位测温法检测到的样品加热可以忽略不计，但在较高进样量下观察到的光谱拖尾可以适应升高的有效准粒子温度。注入电流的整体谱演化在特征上似乎也是非热的，显示出零偏置隧道电导和电导谱下面积的非单调变化。我们讨论这些结果对于自旋极性非平衡分布动态配对断裂场景的一般含义......
Scanning tunneling spectroscopy was performed at 4.2 K on epitaxial thin-film heterostructures comprising YBa2Cu3O7−δ and La0.7Ca0.3MnO3, to study the microscopic effects of spin-polarized quasiparticle injection from the half-metallic ferromagnetic manganite on the high Tc cuprate superconductor. The quasiparticle tunneling characteristics observed were consistent with d-wave pairing symmetry, with a gap-maximum Δ0≈22 meV, up to at least 35 mA (7×103 A/cm2) injection. Spectral smearing observed at higher injections could be fitted to elevated effective quasiparticle temperatures, even though negligible sample heating was detected by in situ thermometry. The overall spectral evolution with the injection current also appears to be nonthermal in character, showing a nonmonotonic change in both the zero-bias tunneling conductance and the area under the conductance spectrum. We discuss general implications of these results for the scenario of dynamic pair breaking by a nonequilibrium distribution of spin-pola...