Quantum Spectra of Hydrogen Atoms in Various Magnetic Fields with the   Closed Orbit Theory
  The quantum spectra of hydrogen atoms in various magnetic fields have been calculated with the closed orbit theory. The magnitude of the magnetic field decreases from 5.96 T to 0.56T with a step of 0.6T. We demonstrate schematically that the closed orbits disappear with the decrease of the magnitude of the magnetic field when the corresponding finite resolution of experiment is fixed. This may give us a good way to control the shape and the number of the closed orbits in the system, and thus to control where a peak should exist in the Fourier transformation of the quantum spectra. 
Liang-You Peng, Xian-Zhou Zhang and Jian-Guo Rao