  Thermodynamic properties of quasiparticles in a graphene-based structures are
investigated. Two graphene superconducting layers (one superconducting
component is placed on the top layeredgraphene structure and the other
component in the bottom) separated by oxide dielectric layers and one normal
graphene layer in the middle. The quasiparticle flow emerged due to external
gate voltage, we considered it as a gas of electron-hole pairs whose components
belong to different layers. This is a striking result in view of the complexity
of these systems: we have established that specific heat exhibits universal
(-T3) behaviour at low T, independent from the gate voltage and the
superconducting gap. The experimental observation of this theoretical
prediction would be an important step towards our understanding of critical
massless matter.
