I was reading a story on phys.org:
Holographic image of a black hole proposed in a graphene flake (Lisa Zyga, 25 July 2018, phys.org)
From there I followed a link to the paper
where I read the following abstract:
Electrons in clean macroscopic samples of graphene exhibit an astonishing variety of quantum phases when strong perpendicular magnetic field is applied. These include integer and fractional quantum Hall states as well as symmetry broken phases and quantum Hall ferromagnetism. Here we show that mesoscopic graphene flakes in the regime of strong disorder and magnetic field can exhibit another remarkable quantum phase described by holographic duality to an extremal black hole in two dimensional anti-de Sitter space. This phase of matter can be characterized as a maximally chaotic non-Fermi liquid since it is described by a complex fermion version of the Sachdev-Ye-Kitaev model known to possess these remarkable properties.
I don't expect someone to explain the whole abstract -- that would be asking too much. But I would like to get oriented enough to "see the forest" without expecting to identify all the trees here.
In that spirit, is the initial description of a solid state system with "an astonishing variety of quantum phases" given in the realm of a quantum field theory? If not in a QFT, does another single theoretical approach describe "integer and fractional quantum Hall states as well as symmetry broken phases and quantum Hall ferromagnetism" -- or are there one or more theories or problem-solving frameworks involved?