We review the mechanism for transport in strongly anharmonic chains of
oscillators near the atomic limit where all oscillators are decoupled. In this
regime, the motion of most oscillators remains close to integrable, i.e.
quasi-periodic, on very long time scales, while a few chaotic spots move very
slowly and redistribute the energy across the system. The material acquires
several characteristic properties of dynamical glasses: intermittency, jamming
and a drastic reduction of the mobility as a function of the thermodynamical
parameters. We consider both classical and quantum systems, though with more
emphasis on the former, and we discuss also the connections with quenched
disordered systems, which display a similar physics to a large extent.Comment: Review paper. Invited submission to the CRAS (special issue on
Fourier's legacy). 16 pages, 3 figure
