The behavior of the electron dephasing time near zero temperature,
, has recently attracted vigorous attention. This renewed interest
is primarily concerned with whether
should reach a finite or an
infinite value as
0. While it is accepted that
should
diverge if there exists only electron-electron (electron-phonon) scattering,
several recent
... [Show full abstract] measurements have found that depends only very
weakly on temperature, if at all, when T is sufficiently low. This article
discusses the current experimental status of "the saturation problem", and
concludes that the origin(s) for this widely observed saturation are still
unresolved.