Holographic D3-probe-D5 Model of a Double Layer Dirac Semimetal
arXiv:1410.4911 · doi:10.1007/JHEP12(2014)091
Abstract
The possibility of inter-layer exciton condensation in a holographic D3-probe-D5 brane model of a strongly coupled double monolayer Dirac semi-metal in a magnetic field is studied in detail. It is found that, when the charge densities on the layers are exactly balanced so that, at weak coupling, the Fermi surfaces of electrons in one monolayer and holes in the other monolayer would be perfectly nested, inter-layer condensates can form for any separation of the layers. The case where both monolayers are charge neutral is special. There, the inter-layer condensate occurs only for small separations and is replaced by an intra-layer exciton condensate at larger separations. The phase diagram for charge balanced monolayers for a range layer separations and chemical potentials is found. We also show that, in semi-metals with multiple species of massless fermions, the balance of charges required for Fermi surface nesting can occur spontaneously by breaking some of the internal symmetry of the monolayers. This could have important consequences for experimental attempts to find inter-layer condensates.
minor correction to references
References in corpus (14)
- Quantum Hall Ferromagnetism in Graphene
- Quantised Vortices in an Exciton-Polariton Fluid
- Landau Level Splitting in Graphene in High Magnetic Fields
- Strong Coulomb drag and broken symmetry in double-layer graphene
- Room-Temperature Superfluidity in Graphene Bilayers
- The zero-energy state in graphene in a high magnetic field
- Dissipative Quantum Hall Effect in Graphene near the Dirac Point
- Exciton condensation and charge fractionalization in a topological insulator film
- Exciton Condensation and Perfect Coulomb Drag
- Excitonic condensation of massless fermions in graphene bilayers
- Divergent resistance at the Dirac point in graphene: Evidence for a transition in a high magnetic field
- Vortices, zero modes and fractionalization in bilayer-graphene exciton condensate
- Holographic Bilayer/Monolayer Phase Transitions
- A Quantum Critical Point from Flavours on a Compact Space