  We study the interface between a fractional topological insulator and an
ordinary insulator, both described using holography. By turning on a chemical
potential we induce a finite density of matter localized at the interface.
These are gapless surface excitations which are expected to have a fermionic
character. We study the thermodynamics of the system, finding a symmetry
preserving compressible state at low temperatures, whose excitations exhibit
hyperscaling violation. These results are consistent with the expectation of
gapless fermionic excitations forming a Fermi surface at finite density.

High Energy Physics - Theory;Strongly Correlated Electrons