Figure 7
From: Creation of two-dimensional Coulomb crystals of ions in oblate Paul traps for quantum simulations
Eigenvalues of the normal modes as a function of
for
. The axial mode frequencies (blue circles) decrease and planar mode frequencies (red triangles) increase as 
increases, as shown in the four cases illustrated: (a) 
, (b) 
, (c) 
and 
and (d) 
. For (b)-(d) the eigenvalues of the normal modes also are closer together at low and separate as increases. The axial frequencies have two degeneracies and the planar frequencies have four degeneracies as discussed in the main text.