Abstract
Recently proposed accurate correlation energies are used to determine the phase diagram of strongly coupled electron-hole graphene bilayers. The control parameters of the phase diagram are the charge carrier density and the insulating barrier thickness separating the bilayers. In addition to the electron-hole superfluid phase we find two new inhomogeneous ground states, a one dimensional charge density wave phase and a coupled electron-hole Wigner crystal. The elementary crystal structure of bilayer graphene plays no role in generating these new quantum phases, which are completely determined by the electrons and holes interacting through the Coulomb interaction. The experimental parameters for the new phases lie within attainable ranges and therefore coupled electron-hole bilayer graphene presents itself as an experimental system where novel emergent many-body phases can be realized.
Highlights
The interplay between superconducting and charge density wave (CDW) phases that is often observed in connection with High-Temperature superconductors, is attracting considerable attention
In this paper we find, besides the superfluid phase discussed in refs 20–23, that there are two new inhomogeneous ground-state phases: (i) a strongly-coupled one-dimensional charge density wave (1D-CDW), and (ii) a coupled electron-hole Wigner crystal (c-WC)
When d decreases below d/aB⁎ = 12, a new CDW phase interposes itself between the Fermi liquid and c-WC
Summary
The interplay between superconducting and charge density wave (CDW) phases that is often observed in connection with High-Temperature superconductors, is attracting considerable attention. The complexity of the crystals in these materials, makes it challenging to identify the competing contributions[1,2,3,4,5] We report in this manuscript on a, by far, simpler system exhibiting the same association of superfluid and CDW phases, but a system in which the polarizable background is uniform, so there is no intricate background structure that could determine the properties of the CDW. There exist several studies pertinent to inhomogeneous phases in coupled two-dimensional-electron-gas (2DEG) layers[6,7,8] Despite these early attempts, there are no studies of the CDW phase for small electron-hole layer separations where interlayer correlation effects will be strong. We consider bilayer graphene embedded in a hexagonal Boron Nitride (h-BN)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
