An innovative model that mirrors the behaviour of atoms in white dwarfs has been created in a lab, allowing scientists to improve their understanding hydrogen on the surface of high-field magnetic white dwarfs. .The approach, presented in Nature Communications this week, demonstrates the possibility of using readily available materials to model astrophysical phenomena.
Understanding the behaviour of atoms under high magnetic fields is an area of intense interest, particularly when it comes to white dwarf stars, where enormous magnetic fields far in excess of those available on Earth are expected to exist. The scale of these fields must be inferred from models that are compared with the atomic spectra measured from the stars. At the same time, the theory surrounding atoms in such large fields is complex and cannot be tested with available magnetic fields. Benedict Murdin and colleagues circumvent this problem by doping phosphorous into silicon, which shows a simple scaling relation between its atomic properties and those of hydrogen. They then compare the spectrum of the phosphorous atoms under laboratory magnetic fields and with those obtained for hydrogen on white dwarf stars. The agreement between them shows that the phosphorous atoms in a magnetic field of tens of tesla behave as though they were hydrogen atoms in a field of tens of tho usands of tesla.
This solid-state system allows the team to verify the theory of hydrogen in high magnetic field without complex simulations or the unobtainable fields, and demonstrates its use as an analogue for modelling atoms in white dwarf stars in the lab.