Using the self-consistent Hartree-Fock approximation, we study the compressibility instability of the interacting electrons in bilayer graphene. The chemical potential and the compressibility of the electrons can be significantly altered by an energy gap (tunable by external gate voltages) between the valence and conduction bands. For zero gap case, we show that the homogeneous system is stable. When the gap is finite, the compressibility of the electron system becomes negative at low carrier doping concentrations and low temperature. The phase diagram distinguishing the stable and unstable regions of a typically gapped system in terms of temperature and doping is also presented.
Shubnikov-de Haas oscillations of high mobility holes in monolayer and bilayer WSe$_2$: Landau level degeneracy, effective mass, and negative compressibility
On the coexistence of antiferromagnetism and d + i d superconducting correlations in the graphene bilayer
我们讨论了蜂窝状单层上的t-J-U模型，该模型具有与石墨烯双层相同的动力学项的低能描述，特别是研究了反铁磁性和超导关联的共存，这些关联起源于没有相位相干的库珀对。我们表明，该模型是相关的石墨烯双层的描述和存在的d + i d超导相关的反铁磁性可以导致二次依赖于小磁场的有效单层的间隙与Velasco等人的运输测量相一致。在石墨烯双层。
