GROUND-STATE OF A SPINLESS CHARGED-PARTICLE IN A PERIODIC MAGNETIC-FIELD

The ground-state energy of a two-dimensional, spinless, charged partic le in a periodic magnetic field is studied by an exact quantum-mechani cal wave-packet propagation method. The periodic magnetic-field modula tion removes the degeneracy of the lowest Landau level, and a cluster of states appears both above and below 1/2 (h) over bar omega(c), the homogeneous field lowest Landau level. With two magnetic flux units th reading through each magnetic unit cell, the lowest Landau level split s into two separate subbands, with three magnetic flux units the lowes t Landau level splits into three separate subbands, and so forth. When a spin energy term is added to the Hamiltonian of the charged particl e in the periodic magnetic field, the lowest Landau level becomes unaf fected by the periodic magnetic field modulation, in agreement with Du brovin and Novikov.