Title: Topological phase transition between composite-fermion and Pfaffian daughter states near ν = 1/2 FQHS Show Chinese title

Title: 复合费米子和佩夫里亚诺次态之间的拓扑相变靠近ν = 1/2 FQHS

Abstract: $\nu$=1/2 is among the most enigmatic many-body phases in two-dimensional electron systems as it appears in the ground-state rather than an excited Landau level. It is observed in wide quantum wells where the electrons have a bilayer charge distribution with finite tunneling. Whether this 1/2 FQHS is two-component (Abelian) or one-component (non-Abelian) has been debated since its experimental discovery over 30 years ago. Here, we report strong 1/2 FQHSs in ultrahigh-quality, wide, GaAs quantum wells, with transport energy gaps up to $\simeq$4K, among the largest gaps reported for any even-denominator FQHS. The 1/2 FQHS is flanked by numerous, Jain-sequence FQHSs at $\nu$=$p$/(2$p$$\pm$1) up to $\nu$=8/17 and 9/17. Remarkably, as we raise the density and strengthen the 1/2 FQHS, the 8/17 and 7/13 FQHSs suddenly become strong, much stronger than their neighboring high-order FQHSs. Insofar as FQHSs at $\nu$=8/17 and 7/13 are precisely the theoretically-predicted, simplest, daughter states of the one-component Pfaffian 1/2 FQHS, our data suggest a topological phase-transition of 8/17 and 7/13 FQHSs from the Jain-states to the daughter states of the Pfaffian, and that the parent 1/2 FQHS we observe is the Pfaffian state. Show Chinese abstract

Abstract: $\nu$=1/2 是二维电子系统中最神秘的多体相之一，因为它出现在基态而不是激发态的 Landau 能级中。它在宽量子阱中被观察到，其中电子具有双层电荷分布且有有限的隧穿效应。自30多年前实验发现以来，这个1/2 FQHS是两组分（阿贝尔）还是单组分（非阿贝尔）一直存在争议。在这里，我们报告了在超高质量、宽的 GaAs 量子阱中出现的强1/2 FQHS，其输运能隙高达$\simeq$4K，是任何偶分母 FQHS 中最大的能隙之一。1/2 FQHS 位于许多 Jain 序列 FQHS 之间，其值为$\nu$=$p$/(2$p$$\pm$ 1) 直到$\nu$=8/17 和 9/17。值得注意的是，当我们提高密度并增强1/2 FQHS时，8/17 和 7/13 FQHS 突然变得很强，比它们相邻的高阶 FQHS 强得多。 就FQHSs在$\nu$=8/17和7/13而言，它们正是理论上预测的、最简单的单组分Pfaffian 1/2 FQHS的子态，我们的数据表明8/17和7/13 FQHSs从Jain态到Pfaffian的子态发生了拓扑相变，并且我们观察到的父态1/2 FQHS是Pfaffian态。