论文标题
在生命涡旋物质中缺乏六角形向平方结构过渡
Absence of hexagonal to square structural transition in LiFeAs vortex matter
论文作者
论文摘要
我们通过扫描隧道显微镜和光谱法研究了两个化学计量生命值样品中的磁涡流。通过测量在0.5至12 t之间样品的零偏置电导率下的局部电子密度（LDOS）来揭示涡旋。从单个涡流光谱学中，我们提取了两个样品的Ginzburg-landau相干长度，为$ 4.4 \ pm0.5 $ nm nm nm and $ nm和$ 4.1 \ pm0.5 $ nm，以$ 4.4 \ pm0.5 $ nm \ nmm0.5 $ nm。但是，与以前的报道相反，我们的研究表明，在现场冷却和零场冷却过程中，据报道的六角形至方形的涡流晶格过渡最多可达12吨。值得注意的是，观察到高度有序的零场冷却六角形涡旋晶格，最多为8 t。我们认为，几个因素可能会确定生命值中涡旋晶格的结构，例如（i）冷却过程的详细信息（ii）样本stoichiementry（ii）示例stoichiementry（ii）示例量化的范围，从而改变了nematic波动的形成（III）详细信息（iii）详细信息（iii）详细信息。
We investigated magnetic vortices in two stoichiometric LiFeAs samples by means of scanning tunneling microscopy and spectroscopy. The vortices were revealed by measuring the local electronic density of states (LDOS) at zero bias conductance of samples in magnetic fields between 0.5 and 12 T. From single vortex spectroscopy we extract the Ginzburg-Landau coherence length of both samples as $4.4\pm0.5$ nm and $4.1\pm0.5$ nm, in accordance with previous findings. However, in contrast to previous reports, our study reveals that the reported hexagonal to square-like vortex lattice transition is absent up to 12 T both in field-cooling and zero-field-cooling processes. Remarkably, a highly ordered zero field cooled hexagonal vortex lattice is observed up to 8 T. We argue that several factors are likely to determine the structure of the vortex lattice in LiFeAs such as (i) details of the cooling procedure (ii) sample stoichiometry that alters the formation of nematic fluctuations, (iii) details of the order parameter and (iv) magnetoelastic coupling.
