Fig. 3: Josephson oscillation frequency versus the interaction parameter.
From: Measurement of the superfluid fraction of a supersolid by Josephson effect
Red dots are the experimental frequencies for Δφ. Filled and open blue dots are the frequencies for Z measured by in situ imaging with and without optical separation, respectively (Methods). Vertical error bars are the uncertainties in the nonlinear fit of the sinusoidal oscillations shown in Fig. 2c,d. Horizontal error bars represent the experimental resolution in εdd (Methods). The red point at εdd = 1.444 is shifted slightly horizontally for clarity. Black points are the results of numerical simulations. The dashed line is a guide for the eye. The insets show the modulated ground-state density profiles obtained from numerical simulations for different values of εdd. The vertical dotted line marks the critical point of the superfluid–supersolid quantum phase transition.
