Figure 3. Inverse-squared magnetic penetration depth.

The temperature dependence of λ⁻² measured at various applied hydrostatic pressures for Ba_0.65Rb_0.35Fe₂As₂. The solid line for p=0 GPa corresponds to a two-gap s-wave model (a) and the solid lines for finite pressure represent a fits to the data using a multiband d-wave model (b–f). The dashed lines in c and f represent fits to the data using the microscopic model. The error bars are calculated as the s.e.m.