Research of Fermi surface properties in uranium compounds without inversion and/or time-reversal symmetry

我们已成功地生长出高质量的铁磁UCu_2Si_2和变磁系统UCoAl单晶。对于UCu_2Si_2，我们也成功地观察到低温铁磁态的de Haas-van Alphen（dHvA）信号。通过测量dHvA信号的角度依赖性，与能带计算结果进行比较，揭示了UCu_2Si_2的电子态。我们对高质量的铁磁超导体UCoGe单晶进行了磁场方向微调的磁阻测量。从这些结果中，我们发现了上临界场H_的反常各向异性<c2>。

We have succeeded in growing a high quality single of ferromagnetUCu_2Si_2 and metamagnetic system UCoAl. In the case of UCu_2Si_2, we also succeeded inobserving the de Haas-van Alphen (dHvA) signal in the ferromagnetic state at low temperatures. From the measurements of angular dependence of dHvA signal, the electronic state of UCu_2Si_2 was revealed by comparison with the band calculation. We performed the magnetoresistivity measurements with fine tuning of the field direction on high quality single crystals of the ferromagnetic superconductor UCoGe. From these results, we found anomalous anisotropy of the upper critical field H_<c2>.