Fig. 2: Josephson oscillations in a supersolid.
From: Measurement of the superfluid fraction of a supersolid by Josephson effect
a, Sketch of the experimental system. The black line is the supersolid density profile at equilibrium. The dashed green line is the optical lattice potential used for the phase imprinting. b, Examples of experimental single shots and corresponding integrated 1D profiles. Top row, interference fringes after a free expansion. Red curves are fit functions used to extract the phase difference Δφ. Bottom row, in situ images. Shaded areas indicate the populations of the left and right halves of the supersolid used to extract the population imbalance Z. c, Oscillations of Z as a function of time at εdd = 1.428. Dots are experimental points. Error bars are the s.e.m. of 20–30 measurements. The solid line is the numerical simulation for the same parameters. The dashed line is a sinusoidal fit to the experimental data. d, Same for Δφ. Experimental values and error bars are calculated using the circular mean and s.e.m. (see Methods).
