  Gauge/gravity duality has proved to be a very successful tool for describing
strongly coupled systems in particle physics and heavy ion physics. The
application of the gauge/gravity duality to quantum matter is a promising
candidate to explain questions concerning non-zero temperature dynamics and
transport coefficients. To a large extent, the success of applications of
gauge/gravity duality to the quark-gluon plasma is founded on the derivation of
a universal result, the famous ratio of shear viscosity and entropy density. As
a base for applications to condensed matter physics, it is highly desirable to
have a similar universal relation in this context as well. A candidate for such
a universal law is given by Homes' law: High Tc superconductors, as well as
some conventional superconductors, exhibit a universal scaling relation between
the superfluid density at zero temperature and the conductivity at the critical
temperature times the critical temperature itself. In this work we describe
progress in employing the models of holographic superconductors to realize
Homes' law and to find a universal relation governing strongly correlated
quantum matter. We calculate diffusive processes, including the backreaction of
the gravitational matter fields on the geometry. We consider both holographic
s-wave and p-wave superconductors. We show that a particular form of Homes' law
holds in the absence of backreaction. Moreover, we suggest further steps to be
taken for holographically realizing Homes' law more generally in the presence
of backreaction.
