Hyperuniformity characterizes a state of matter for which densityfluctuations diminish towards zero at the largest length scales. However, thetask of determining whether or not an experimental system is hyperuniform isexperimentally challenging due to finite-resolution, noise and sample-sizeeffects that influence characterization measurements. Here we explore theseissues, employing video optical microscopy to study hyperuniformity phenomenain disordered two-dimensional jammed packings of soft spheres. Using acombination of experiment and simulation we characterize the detrimentaleffects of particle polydispersity, image noise, and finite-size effects on theassignment of hyperuniformity, and we develop a methodology that permitsimproved diagnosis of hyperuniformity from real-space measurements. The key tothis improvement is a simple packing reconstruction algorithm that incorporatesparticle polydispersity to minimize free volume. In addition, simulations showthat hyperuniformity can be ascertained more accurately in direct space than inreciprocal space as a result of finite sample-size. Finally, experimentalcolloidal packings of soft polymeric spheres are shown to be hyperuniform.
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