  Electronic systems harboring one dimensional helical modes, where the spin
and momentum of the electron are locked, have lately become an important field
of its own. When coupled to a conventional superconductor, such systems are
expected to manifest topological superconductivity, a unique phase that gives
rise to exotic Majorana zero modes. Even more interesting are fractional
helical states which have not been observed before and which open the route for
the realization of the generalized para fermions quasiparticles. Possessing non
abelian exchange statistics, these quasiparticles may serve as building blocks
in topological quantum computing. Here, we present a new approach to form
protected one dimensional helical and fractional helical edge modes in the
quantum Hall regime. The novel platform is based on a carefully designed double
quantum well structure in a high mobility GaAs based system. In turn, the
quantum well hosts two sub bands of 2D electrons, each tuned to the quantum
Hall effect regime. By electrostatic gating of different areas of the
structure, counter propagating integer, as well as fractional, edge modes,
belonging to Landau levels with opposite spins are formed, rendering the modes
helical. We demonstrate that due to spin protection, these helical modes remain
ballistic, without observed mixing for large distances. In addition to the
formation of helical modes, this new platform can be exploited as a rich
playground for an artificial induction of compounded fractional edge modes, as
well as construction of interferometers based on chiral edge modes.
