New chiral phases of superfluid 3He stabilized by anisotropic silica aerogel
New chiral phases of superfluid 3He stabilized by anisotropic silica aerogel
复制标题
各向异性二氧化硅气凝胶稳定超流体 3He 的新手性相
作者：
J. Pollanen;J.I.A. Li;C. A. Collett;W. Gannon;W. Halperin;J. Sauls
在二氧化硅气凝胶中的液体3He没有表现出在体3He中存在的手性超流相的痕迹。轴向拉伸气凝胶引入了稳定手性相的各向异性，支持在低温下向新的无序相的转变。各种各样的费米系统通过形成束缚对而凝聚，包括高温1和重费米子2超导体、Sr2RuO4（参考文献3）、冷原子气体4和超流3He（参考文献5）。其中一些形成具有非零轨道角动量的奇异量子态。我们已经发现，在3He的情况下，由高度多孔的二氧化硅气凝胶设计的各向异性无序，稳定了否则不会存在的手性超流体状态。此外，我们发现，这种状态的手征轴可以与垂直于气凝胶各向异性轴的磁场的应用程序的唯一取向。在足够低的温度下，我们观察到从均匀取向的手性状态到与局部有序域一致的无序结构的急剧转变，与超流玻璃相的预期相反6。
Liquid 3He in silica aerogel exhibits no trace of the chiral superfluid phase present in bulk 3He. Stretching the aerogel axially introduces an anisotropy that stabilizes the chiral phase, supporting a transition to a new disordered phase at low temperatures. A rich variety of Fermi systems condense by forming bound pairs, including high-temperature1 and heavy-fermion2 superconductors, Sr2RuO4 (ref. 3), cold atomic gases4 and superfluid 3He (ref. 5). Some of these form exotic quantum states with non-zero orbital angular momentum. We have discovered, in the case of 3He, that anisotropic disorder, engineered from highly porous silica aerogel, stabilizes a chiral superfluid state that otherwise would not exist. Furthermore, we find that the chiral axis of this state can be uniquely oriented with the application of a magnetic field perpendicular to the aerogel anisotropy axis. At sufficiently low temperature we observe a sharp transition from a uniformly oriented chiral state to a disordered structure consistent with locally ordered domains, contrary to expectations for a superfluid glass phase6.