Ground and first excited states. Ground and first excited state energies of the electron (colored lines) as functions of the (a) inner and (b) outer radii of the QR for L=20 nm, P=0, and F=0. The impurity is placed at zi = 0 and ρi = (R1 + R2)/2. The insets show the corresponding energy difference between the 2s and 1s states.
Barseghyan et al. Nanoscale Research Letters 2012 7:538 doi:10.1186/1556-276X-7-538