Unusual Hall Effect in Superconducting MgB$_2$ Films: Analogy to High-T$_c$ Cuprates
Unusual Hall Effect in Superconducting MgB$_2$ Films: Analogy to High-T$_c$ Cuprates
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DOI：
10.1103/physrevb.64.220506
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发表时间：
2001-04
期刊：
影响因子：
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通讯作者：
R. Jin;M. Paranthaman;H. Zhai;H. Christen;D. Christen;D. Mandrus
中科院分区：
文献类型：
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作者：
R. Jin;M. Paranthaman;H. Zhai;H. Christen;D. Christen;D. Mandrus
本文研究了两种超导MgB 2薄膜（T $c0 $= 38.0K）在正常态和超导态下的霍尔系数随温度和磁场的变化关系。结果表明，正常态霍尔系数R$_H$为正，且随温度的降低而增大，与外加磁场无关。在T$_c$（H）以下，R$_H$随温度迅速减小，并在达到零之前改变符号。R$_H$显示最小值的位置和幅度取决于所施加的场。对实验数据的定量分析表明，MgB 2的霍尔响应与高T c铜酸盐的霍尔响应非常相似：正常态下的R H T和cot H T，混合态下的R H T和cot H T符号相反.这表明MgB_2中的B-B层与高Tc铜酸盐中的Cu-O平面一样，对电输运性质起着重要作用。
We have investigated the temperature and magnetic field dependence of the Hall coefficient of two well-characterized superconducting MgB$_2$ films (T$_{c0}$=38.0 K) in both the normal and superconducting states. Our results show that the normal-state Hall coefficient R$_H$ is positive and increases with decreasing temperature, independent of the applied magnetic field. Below T$_c$(H), R$_H$ decreases rapidly with temperature and changes sign before it reaches zero. The position and magnitude at which R$_H$ shows a minimum depends on the applied field. Quantitative analysis of our data indicates that the Hall response of MgB$_2$ behaves very similarly to that of high-T$_c$ cuprates: R$_H$ $\propto$ T and cot$\theta_H$ $\propto$ T$^2$ in the normal state, and a sign reversal of R$_H$ in the mixed state. This suggests that the B-B layers in MgB$_2$, like the Cu-O planes in high-T$_c$ cuprates, play an important role in the electrical transport properties.