Strongly correlated materials exhibit unconventional phases and
mechanisms which cannot be explained within the standard condensed matter framework.
Holographic theories provide a new and promising tool to shed light on these phenomena.
I will motivate the duality between gravitational theories and
real quantum materials using a phenomenological attitude.
Incorporating momentum relaxation into these kind of theories has been a pressing issue
which has been recently solved by mean of massive gravity.
I will show how the graviton mass can provide an holographic dual for the Drude model.
I will comment further about a simple generalization that exhibits an interaction-driven Metal-Insulator transition (MIT).
The transition is triggered by the formation of polarons -- phonon-electron quasi-bound states that dominate the conductivities. Interestingly enough there are experimental hints which underline the role of polarons for MIT in manganite materials.