Insulator-to-Conducting Transition in Dense Fluid Helium

P. M. Celliers, P. Loubeyre, J. H. Eggert, S. Brygoo, R. S. McWilliams, D. G. Hicks, T. R. Boehly, R. Jeanloz, G. W. Collins
2010 Physical Review Letters  
By combining diamond-anvil-cell and laser-driven shock wave techniques, we produced dense He samples up to 1:5 g=cm 3 at temperatures reaching 60 kK. Optical measurements of reflectivity and temperature show that electronic conduction in He at these conditions is temperature-activated (semiconducting). A fit to the data suggests that the mobility gap closes with increasing density, and that hot dense He becomes metallic above $1:9 g=cm 3 . These data provide a benchmark to test models that
more » ... st models that describe He ionization at conditions found in astrophysical objects, such as cold white dwarf atmospheres.
doi:10.1103/physrevlett.104.184503 pmid:20482179 fatcat:ihazq5c7rjd67h6pmlfa2mazqy