论文标题
氧化物超晶格中极化涡流晶体和手性相变的熔化
Melting of Polarization Vortices Crystals and Chiral Phase Transitions in Oxide Superlattices
论文作者
论文摘要
我们在（pbtio $ _3 $）$ _ n $/（srtio $ _3 $）$ _ n $ superlattices中研究了两极分化涡流的平衡安排。我们发现，在低温下，极化涡流以常规排列组织，在该布置中，顺时针和逆时针方向的涡旋交替位置，从而导致具有明确的手工的晶体状结构。这种手性晶体在临界温度下融化$ t_ \ mathrm {m} $中的手性液体，其中丢失了远距离顺序，但保留了交接。在较高的温度下，$ t_ \ mathrm {c} $，第二阶段过渡发生，偏振涡流的手性液体失去了手段。两种相变可以通过订单参数的足够选择来容易地识别。
We study the equilibrium arrangements of polarization vortices in (PbTiO$_3$)$_n$/(SrTiO$_3$)$_n$ superlattices by means of second-principles simulations. We find that, at low temperatures, polarization vortices organize in a regular arrangement in which clockwise and counter-clockwise vortices alternate positions, leading to a crystal-like structure with well defined handedness. This chiral crystal melts at a critical temperature $T_\mathrm{M}$ into a chiral liquid, where long-range order is lost but handedness is preserved. At even higher temperatures, $T_\mathrm{C}$, a second phase transition occurs, at which the chiral liquid of polarization vortices loses its handedness. Both phase transitions can be readily identified by the adequate choices of order parameters.
