Fig. 2: Model of exciton condensation in 2D bilayer heterostructure.
From: Heterobilayers of 2D materials as a platform for excitonic superfluidity
a Binding energies (lines labeled by meV) and exciton radius (color map) in a metallic bilayer with interlayer separation d = 3 Å as a function of reduced effective mass μ and carrier density n. Highlighted area shows the region with bound states. b Phase diagram for excitons in bilayer semimetal. BKT line for transition to quasi-condensate and BCS line for different reduced mass (0.125, 0.25, and 0.5) are shown (equal carrier masses are assumed). Outside of the condensate region, a degenerate exciton Bose gas (DEBG) exists on the low density side, and electron-hole plasma on the high density side. The estimated critical temperatures (Tc) for materials labeled (1, 2, and 3) in Fig. 3 are also shown.
