Figure 1

(a) Sketch of the bilayer graphene lattice structure with the interlayer chiral superconducting correlations (illustrated by wavy lines) between electrons of different types of sublattices. Dirac-cone bands of two monolayers of graphene on the valleys $K_1$ and $K_2^{\prime }$ (right panel), with two states of wave vector $|k⟩$ and $|-k⟩$, which are coherent superpositions of the sublattice pseudospin states $|A_{1,2}⟩$ and $|B_{1,2}⟩$. The interlayer pairing between $|\pm k⟩$ is asymmetrically partial, since only $|A_1⟩$ and $|B_2⟩$ components are paired. (b) The mean field phase diagram of the chiral superconductivity showing dependence on the interlayer hopping energy $t_{\perp }$ and the temperature $T$ for a pure bilayer graphene ($\mu =0$). The line of transition from $N$ to $S$ phases is shown in which dashed and solid parts indicate the first- and the second-order transitions, respectively. A color plot of the PG is also presented. (c) The resulting gapless $S$ band structure along $k_y$ for undoped bilayer graphene and for $t_{\perp }=0.13t$.Reuse & Permissions

Figure 2

Exotic thermodynamic properties of the chiral superconductivity. (a) Pairing gap versus $T$ for $t_{\perp }/t=0.0$, 0.13, 0.2, and 0.34 (from top to bottom). (c) Difference in entropies of $N$ and $S$ states versus $T$ for the same values of parameters as in (a).Reuse & Permissions

Figure 3

Stability of the exotic chiral superconducting states. Difference in thermodynamic potentials of $N$ and $S$ states versus the pairing gap calculated at different temperatures for interlayer hopping energies $0.1t$ (a) and $0.18t$ (b).Reuse & Permissions