ν=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 ≃4K, among the largest gaps reported for any even-denominator FQHS.
The 1/2 FQHS is flanked by numerous, Jain-sequence FQHSs at
ν=p/(2p±1) up to ν=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 ν=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.Comment: 19 pages, 9 figure