Fig. 2: Sampling a two-dimensional Gaussian distribution on the SPU.

Measurements of the voltages of two coupled cells of the SPU were taken at a rate of 12 MHz. Top Left: histogram of the marginal of cell i. Top right: Absolute error between the target covariance matrix and the device covariance matrix (abbreviated as Cov.), similarly for the skewness and kurtosis (respectively abbreviated as Skew. and Kurt.), all calculated using the Frobenius norm. Bottom Left: Scatter plot of voltage samples from both cells. Bottom Right: Histogram of the marginal of cell j. For the marginal plots, the theoretical target marginal is overlaid as a solid red curve. Similarly, for the two-dimensional plot, the theoretical curve corresponding to two standard deviations from the mean is overlaid as a solid red curve. Source data are provided as a Source Data file.