Meek, S. A. Research Group of Precision Infrared Spectroscopy, MPI for Biophysical Chemistry, Max Planck Society;
http://journals.aps.org/pra/pdf/10.1103/PhysRevA.71.065402 (Verlagsversion)
Meek, S. A., Abraham, E. R. I., & Shafer-Ray, N. E. (2005). Impossibility of a biased Stark trap in two dimensions. Physical Review A, 71(6): 065402. doi:10.1103/PhysRevA.71.065402.