Towards holographic flat bands

TL;DR

This paper develops a holographic model inspired by flat-band Dirac systems, revealing an instability towards a nematic phase with anomalous Hall effect and spectral weight shifts, thus providing insights into quantum phases in condensed matter analogs.

Contribution

It constructs a holographic model that captures symmetry breaking and phase transitions akin to flat-band Dirac systems, including backreaction effects and critical phenomena.

Findings

Geometry is unstable towards a nematic phase.

Nematic phase exhibits an anomalous Hall effect.

Spectral weight shows a Drude-like shift.

Abstract

Motivated by the phenomenology in the condensed-matter flat-band Dirac systems, we here construct a holographic model that imprints the symmetry breaking pattern of a rather simple Dirac fermion model at zero chemical potential.In the bulk we explicitly include the backreaction to the corresponding Lifshitz geometry and compute the dynamical critical exponent. Most importantly, we find that such a geometry is unstable towards a nematic phase, exhibiting an anomalous Hall effect and featuring a Drude-like shift of its spectral weight. Our findings should motivate further studies of the quantum phases emerging from such holographic models.