COHERENT STATES COMPOSED OF STARK EIGENFUNCTIONS OF THE HYDROGEN-ATOM

It is well known that for the nonrelativistic hydrogen atom it is poss ible to separate the Schrodinger equation in parabolic as well as sphe rical coordinates. The eigenfunctions obtained in these coordinate sys tems are each a suitable basis set in the absence of an electric field , but only the parabolic states, the Stark eigenfunctions, retain thei r character in the presence of a weak field. The properties of coheren t superpositions of these Stark states are investigated and the motion of the resulting wave packet described. It is shown that a properly c onstituted superposition will mimic classical motion. It is also shown that the constant energy separation between adjacent Stark states of a given principal quantum number leads to periodic motion. In general, they split into distinct ''clumps'' of probability, but revive to for m a single packet after each period. It is, however, possible to const ruct a packet that maintains its shape for all time. (C) 1997 American Association of Physics Teachers.