Scientists are using laser-cooled ions to simulate how dead stars freeze their cores into giant crystals.
March 17, 2026
Original Paper
Measuring impurity-induced shifts in Coulomb crystallization
arXiv · 2603.14980
The Takeaway
The cores of white dwarfs and neutron stars are so dense they eventually crystallize, but we can't observe this process directly. This lab experiment shows that even a tiny amount of 'impurity' atoms can drastically shift the temperature at which a whole star solidifies.
From the abstract
We report a laboratory measurement of how impurities shift Coulomb crystallization in a strongly interacting ionic system. This is achieved by using laser cooled Ca$^+$ crystals doped with a controlled number of Xe$^{12+}$ highly charged ions. We find that the crystallization threshold is unchanged at low impurity concentration, but shows a clear crossover once the impurity content becomes sufficiently large, after which the shift grows approximately linearly. Complementary measurements reveal t