New Publication: “Disorder-induced heating of ultracold neutral plasmas created from atoms in partially filled optical lattices”

The fabrication of ever-shrinking semi-conductor devices requires focused ion milling sources with smaller and smaller resolution. To achieve the sub-nanometre focusing potential of a cold atom electron and ion source (orders of magnitude smaller than thermal sources) will require the removal of any heating mechanisms, such as disorder-induced heating. One way of overcoming this effect is to place atoms in a structured array created with a 3D optical lattice. Experimentally filling 100% of lattice sites is, however, extremely challenging. Here we calculate the heating for fillings from 0 to 99%, showing that even imperfect filling can still lead to a large reduction in the negative effects of disorder-induced heating.

Reference: D. Murphy, B. M. Sparkes, Physical Review E 94, 021201(R) (2016) [pdf]

a) Illustration of lattice filling fractions ranging from small (f=0.1) to high (f=0.9). b) The temperature of ions following ionisation, with the increase due to disorder-induced heating. Higher filling fractions (and therefore more ordered systems) correspond to lower final temperatures.