Universal versus non-universal features in electronic ballistic transport

The interplay between the use of random matrix theory and the semiclassical approach to describe conductance fluctuations in the ballistic regime is discussed. In order to understand the universal behavior as well as the correct physical scalings of conductance correlators one needs both theories. It is shown that, despite of the difficulties to improve the accuracy of the semiclassical theory to handle small energy scales, this approach is rather efficient to understand issues beyond the scope of random matrix modelling. This paper presents some examples where experimental results can, in principle, be fully understood by using the strengths of both approaches.