Fig. 5.

An exoplanet size demographics histogram up to $R/R(E)=6$ ($R$: radius, $R(E)$: Earth’s radius; Bottom) shown together with the implications of our experiments on the radius cliff (Top). Schematic diagrams for the structures of sub-Neptunes with $P(\mathrm{AMB})<15$ GPa and $P(\mathrm{AMB})>25$ GPa are shown (AMB: atmosphere–magma boundary). In the histogram, three horizontal bars show the estimated radii of sub-Neptunes (2 wt% H${}_2$ atmosphere with an Earth-like interior composition) for different pressures (in GPa) at the atmosphere–magma boundary (see SI Appendix, Text 5 for method).