Optical conductivity and superconductivity in LaSb2
Optical conductivity and superconductivity in LaSb2
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LaSb2 的光导率和超导性
DOI：
10.1088/1742-6596/273/1/012151
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
D. van der Marel
中科院分区：
文献类型：
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作者：
J. Ditusa;V. Guritanu;S. Guo;D. Young;P. Adams;R. Goodrich;J. Chan;D. van der Marel
我们测量了LaSb 2的电阻率、电导率和磁化率，以寻找导致超大线性磁阻的线索，并探索超导态的性质。我们没有发现任何证据的光学电导率的电荷密度波状态的形成高于20 K，尽管高度分层的晶体结构。此外，只有很小的变化与磁场的光学反射率观察表明MR是由于散射率，而不是电荷密度，随场的变化。虽然超导基态以前报道低于0.4 K的临界温度，我们观察到，在环境压力下，一个脆弱的超导转变，在2.5 K开始。在晶体样品中，我们发现一个高度的可变性与少数样品显示完整的迈斯纳分数低于0.2 K和波动明显高达2.5 K。压力的应用稳定了超导转变，并降低了超导相的各向异性。
We have measured the resistivity, optical conductivity, and magnetic susceptibility of LaSb2 to search for clues as to the cause of the extraordinarily large linear magnetoresistance and to explore the properties of the superconducting state. We find no evidence in the optical conductivity for the formation of a charge density wave state above 20 K despite the highly layered crystal structure. In addition, only small changes to the optical reflectivity with magnetic field are observed indicating that the MR is due to scattering rate, not charge density, variations with field. Although a superconducting ground state was previously reported below a critical temperature of 0.4 K, we observe, at ambient pressure, a fragile superconducting transition with an onset at 2.5 K. In crystalline samples, we find a high degree of variability with a minority of samples displaying a full Meissner fraction below 0.2 K and fluctuations apparent up to 2.5 K. The application of pressure stabilizes the superconducting transition and reduces the anisotropy of the superconducting phase.