Solutions of the Dirac wave equation are obtained representing the motion of an electron in a uniform magnetic field. These solutions are used to calculate the maximum penetration of the electrons into the field and also the average x coordinate of the current. Both results agree with the classical result to distances of the order of a de Broglie wave length.
The solutions were then combined to represent a beam of electrons passing thru a slit. It was shown that the deviation of this beam from the classical path was also of the order of a de Broglie wave length. It was necessary to impose the condition that the slit be wide compared to an electron wave length - a condition amply fulfilled in all applications. This means that the slit must be so wide that diffraction of the electrons can be neglected.
The conclusion is drawn that in all experiments which have been performed the differences between the classical and the quantum predictions will be too small to be observed. The differences in paths predicted will in all cases be of the order of an electron wave length.
