We investigate non-equilibrium transport in the reentrant integer quantum
Hall phases of the second Landau level. At high currents, we observe a
transition from the reentrant integer quantum Hall phases to classical
Hall-conduction. Surprisingly, this transition is markedly different for the
hole- and electron sides of each spin-branch. While the hole bubble phases
exhibit a sharp transition to an isotropic compressible phase, the transition
for the electron side occurs via an intermediate phase. This might indicate a
more complex structure of the bubble phases than currently anticipated, or a
breaking of the particle-hole symmetry. Such a symmetry breaking in the second
Landau level might also have consequences for the physics at filling factor
ν=5/2.Comment: 11 pages Supplemental Material available at
http://link.aps.org/supplemental/10.1103/PhysRevB.91.19541