Spontaneous formation and relaxation of spin domains in antiferromagnetic spin-1 condensates
Spontaneous formation and relaxation of spin domains in antiferromagnetic spin-1 condensates
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DOI：
10.1038/s41467-019-08505-6
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发表时间：
2019-03-29
影响因子：
16.6
通讯作者：
Gerbier, F.
中科院分区：
文献类型：
--
作者：
Jimenez-Garcia, K.;Invernizzi, A.;Gerbier, F.
低温下的多体系统通常将自己组织成有序相，其性质和对称性由有序参数捕获。在最简单的情况下，例如铁磁材料的宏观磁化，这个序参量在空间上是均匀的。自然界中也存在不均匀的情况，例如在反铁磁性材料中，其中磁化在空间中交替，或者在强相关材料中流动电子出现的所谓条纹相中。理解这种非均匀有序态在多体物理学中是至关重要的。本文在纳米开尔文温度下，实验研究了自旋为1的巡回玻色子的磁有序性。我们证明自旋域自发形成，这纯粹是因为原子之间的反铁磁相互作用，在没有外部磁力的情况下，经过相分离转变。此外，我们还探讨了平衡域构型是如何从远离平衡的初始状态产生的。
Many-body systems at low temperatures generally organize themselves into ordered phases, whose nature and symmetries are captured by an order parameter. This order parameter is spatially uniform in the simplest cases, for example the macroscopic magnetization of a ferromagnetic material. Non-uniform situations also exist in nature, for instance in antiferromagnetic materials, where the magnetization alternates in space, or in the so-called stripe phases emerging for itinerant electrons in strongly correlated materials. Understanding such inhomogeneously ordered states is of central importance in many-body physics. Here we study experimentally the magnetic ordering of itinerant spin-1 bosons in inhome-geneous spin domains at nano-Kelvin temperatures. We demonstrate that spin domains form spontaneously, that is purely because of the antiferromagnetic interactions between the atoms and in the absence of external magnetic forces, after a phase separation transition. Furthermore, we explore how the equilibrium domain configuration emerges from an initial state prepared far from equilibrium.