INVESTIGATION ON NEW ORDERED PHASES OF FERMI AND BOSE PARTICLES UNDER COMPLEX ULTRA-CONDITIONS

对玻色-爱因斯坦凝聚中量子化涡旋的观察使我们进一步考虑这个问题：为了看到BEC中涡旋的内禀不稳定性，我们提出了几个涡旋成核理论。实验测得的成核角速度与其他人基于托马斯费米近似的估计值相差甚远，但我们的微观理论给出了一个合理的值。我们还研究了最近在中等压力下在一种新的重费米子材料UGe 2中观察到的铁磁性和超导性之间的共存问题。在这种材料中，铁磁相中建立的巨大交换内部场几乎肯定会排除单线态配对，导致非幺正三线态配对。我们研究了与配对状态相关的各种奇异特性。

Observation of the quantized vortex in Bose-Einstein condensation leads us to further consider this problem : In order to see the intrinsic instability of a vortex in BEC, while we claim to occur in this system, we propose several theories on vortex nucleation. The observed nuleation angular velocity is far from the estimate done by others based on the Thomas Fermi approximation, but our microscopic theory gives a reasonable value. Future study of this vortex nucleation problem may shed further light on this long-standing issue.We also have investigated the coexistence problem between ferromagnetism and superconductivity, which is recently observed in a new heavy Fermion material : UGe2 under moderate pressure. Gigantic exchange internal field built in ferromagnetic phase in this material almost certainly excludes singlet pairing, leading to a non-unitary triplet pairing. We examine various exotic characteristics associated with the pairing state.