  The Gardner transition is the transition that at mean-field level separates a
stable glass phase from a marginally stable phase. This transition has
similarities with the de Almeida-Thouless transition of spin glasses. We have
studied a well-understood problem, that of disks moving in a narrow channel,
which shows many features usually associated with the Gardner transition.
However, we can show that some of these features are artifacts that arise when
a disk escapes its local cage during the quench to higher densities. There is
evidence that the Gardner transition becomes an avoided transition, in that the
correlation length becomes quite large, of order 15 particle diameters, even in
our quasi-one-dimensional system.
