论文标题
在磁场上的晶体和准碘梯子上相互作用的玻色子
Interacting Bosons on Crystalline and Quasiperiodic Ladders in a Magnetic Field
论文作者
论文摘要
我们研究各种霍夫史塔梯子,以探测相互作用,施加的磁场与晶体或准膜状几何形状之间的相互作用。当存在磁场时,将在带电的颗粒上诱导旋转运动,这可能导致晶格上电流的外在分布。通常,假定梯子晶格的几何形状是均匀的。但是,在这项工作中,我们还将研究具有不均匀键长的梯子,以研究局部电流的形成。通过使用密度矩阵ren量量量应该集体(DMRG)来表征量子相,我们确认了通常的涡流和米斯纳分布的存在,其中颗粒分别在散装内和边缘周围循环。此外,还可以观察到这些模式的变化。将涡流和Meissner顺序结合在一起,以及对于晶格的某些填充物的不可压缩域的发作。如果梯子的键长波动,我们发现与电流结构有很大的差异。这是不均匀,有效的磁通量的结果,导致整个晶格整体的电流优先定位,向较小的键长。然后,我们发现不可压缩的域可以在整个参数空间中大小的尺寸显着增长,并且电流不再具有跨梯子纵向的扩展结构。
We study a variety of Hofstadter ladders in order to probe the interplay between interactions, an applied magnetic field and crystalline or quasiperiodic geometries. Rotational motion will be induced on charged particles when a magnetic field is present, which can result in exotic distributions of current on a lattice. Typically, the geometry of a ladder lattice is assumed to be homogeneous. In this work, however, we will also study ladders that possess non-uniform bond lengths, in order to study the formation of localised currents. By using Density Matrix Renormalisation Group (DMRG) to characterise the quantum phases, we confirm the presence of the usual vortex and Meissner distributions of current, in which particles circulate within the bulk and around the edge respectively. Furthermore, it is also possible to observe variations to these patterns; which combine both vortex and Meissner order, and the onset of incompressible domains for certain fillings of the lattice. If the bond lengths of a ladder fluctuate, we find substantial differences to the structure of currents. This is a consequence of an inhomogeneous, effective magnetic flux, resulting in preferential localisation of currents throughout the lattice bulk, towards the smaller bond lengths. We then find that incompressible domains can significantly grow in size extent across the parameter space, with currents no longer possessing an extended structure across the longitudinal direction of the ladder.