#proton-radius

#proton-radius

General Relativity has yet to let us down. Its success rate is 100%, from tabletop experiments to gravitational lensing and the formation of the great cosmic web.

A core question we want to understand is where did matter come from. And then, if you know about antimatter, it's natural to ask, why is that not here? The process is not understood and we are hunting for clues as to why it happened, says Dr Christian Smorra, a physicist on the Baryon Antibaryon Symmetry Experiment (Base) at Cern.

According to Einstein's General Relativity, for every black hole that exists within the Universe, there are only three properties that go into it that matter in any way: the black hole's total mass, the black hole's net electric charge, and the black hole's intrinsic angular momentum, and that's it. It doesn't matter what type of matter went into the black hole in order to form it; all that matters is its mass, charge, and angular momentum.

Analogue quantum simulations are a useful tool for investigating these systems, particularly in regimes in which the applicability of numerical techniques is limited. For different simulator platforms, figures of merit include the electron bandwidth and interaction strength, temperature and the number of simulated lattice sites. Their use is further underscored by the ability to realize distinct lattice geometries, on-site degrees of freedom and by the physical observables that are accessible to experimental measurement.

A team based at the University of Vienna put individual clusters of around 7,000 atoms of sodium metal some 8 nanometres wide into a superposition of different locations, each spaced 133 nanometres apart. Rather than shoot through the experimental set up like a billiard ball, each chunky cluster behaved like a wave, spreading out into a superposition of spatially distinct paths and then interfering to form a pattern researchers could detect.

Y.W. designed the experimental protocols, performed experiments, analysed the data and wrote the manuscript. Y.H., X.K., D.C., J.X.X. and W.Z. performed experiments and edited the manuscript. Y.C. and S.P. edited the manuscript. M.J., X.P. and J.D. proposed the experimental concept, designed experimental protocols and proofread and edited the manuscript. All authors contributed with discussions and checking the manuscript. Corresponding authors Correspondence to Min Jiang or Xinhua Peng.