Quantum manifestations of closed orbits in the photoexcitation scaled spectrum of the hydrogen atom in crossed fields

The scaled photoexcitation spectrum of the hydrogen atom in crossed electri c and magnetic fields has been obtained by means of accurate quantum mechan ical calculation using a new algorithm. Closed orbits in the corresponding classical system have also been obtained, using a new, efficient and practi cal searching procedure. Two new classes of closed orbit have been identifi ed. Fourier transforming each photoexcitation quantum spectrum to yield a p lot against scaled action has allowed direct comparison between peaks in su ch plots and the scaled action values of closed orbits, Excellent agreement has been found with all peaks assigned.