Electron Circulation in a Magnetic Field

The changes in sign that occur under rotation around the z-axis.

If there is a low-lying orbital of the correct symmetry, the applied field may induce the circulation of the electrons in a complex and hence generate orbital angular momentum. This diagram shows the way in which circulation may arise when the field is applied perpendicular to the xy-plane (perpendicular to this page).
Rotation about the z axis results in the d_x2-y2 moving into the d_xy and then into the d_x2-y2 and then into the d_xy and so on.

Orbital-orbital overlap and SALC Homepage