Phase diagram of vortices in the polar phase of spin-1 Bose-Einstein condensates
Phase diagram of vortices in the polar phase of spin-1 Bose-Einstein condensates
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自旋 1 玻色-爱因斯坦凝聚极相中涡旋的相图
DOI：
10.1103/physreva.104.013316
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发表时间：
2021
影响因子：
2.9
通讯作者：
Takeuchi Hiromitsu
中科院分区：
文献类型：
--
作者：
Fa Shixin;Yamamoto Masanori;Nishihara Hirotomo;Sakamoto Ryota;Kamiya Kazuhide;Nishina Yuta;Ogoshi Tomoki;坂本 良太;Takeuchi Hiromitsu
从理论上研究了自旋为1的玻色-爱因斯坦凝聚极相中最低能量涡旋的相图。单量子化的涡被归类的本地有序状态的涡核和三种类型的涡被发现作为最低能量的涡，这是椭圆AF核涡，轴对称F核涡，和N核涡。这些涡旋以局部有序状态、铁磁（F）、反铁磁（AF）、破轴对称（BA）和正常（N）状态命名，而不包括体极（P）状态。N核涡旋是一种常规涡旋，在其核内超流序参量为零。当二次塞曼能量小于某一临界值时，另外两种涡是稳定的。轴对称的F核涡旋是铁磁相互作用中能量最低的涡旋，它的F核被BA皮包围，形成铁磁自旋织构，如局部Mermin-Ho织构所示。反铁磁相互作用使椭圆形的AF核涡旋稳定，涡旋核局部具有向列自旋和铁磁序，并且由跨越两个BA边缘之间的AF核孤子组成。从N核涡到其他两个涡的相变是连续的，而AF核和F核涡之间的相变是不连续的。通过Bogoliubov理论的微扰分析计算了连续涡核转变的临界点，并用Ginzburg-Landau形式描述了临界行为。还研究了俘获势对芯结构的影响。
The phase diagram of lowest-energy vortices in the polar phase of spin-1 Bose-Einstein condensates is investigated theoretically. Singly quantized vortices are categorized by the local ordered state in the vortex core and three types of vortices are found as lowest-energy vortices, which are elliptic AF-core vortices, axisymmetric F-core vortices, and N-core vortices. These vortices are named after the local ordered state, ferromagnetic (F), antiferromagnetic (AF), broken-axisymmetry (BA), and normal (N) states apart from the bulk polar (P) state. The N-core vortex is a conventional vortex, in the core of which the superfluid order parameter vanishes. The other two types of vortices are stabilized when the quadratic Zeeman energy is smaller than a critical value. The axisymmetric F-core vortex is the lowest-energy vortex for ferromagnetic interaction, and it has an F core surrounded by a BA skin that forms a ferromagnetic-spin texture, as exemplified by the localized Mermin-Ho texture. The elliptic AF-core vortex is stabilized for antiferromagnetic interaction; the vortex core has both nematic-spin and ferromagnetic orders locally and is composed of the AF-core soliton spanned between two BA edges. The phase transition from the N-core vortex to the other two vortices is continuous, whereas that between the AF-core and F-core vortices is discontinuous. The critical point of the continuous vortex-core transition is computed by the perturbation analysis of the Bogoliubov theory and the Ginzburg-Landau formalism describes the critical behavior. The influence of trapping potential on the core structure is also investigated.