TRANSMISSION RESONANCES IN MAGNETIC-BARRIER STRUCTURES

Quantum transport properties of electrons in simple magnetic-barrier ( MB) structures and in finite MB superlattices are investigated in deta il. It is shown that there exists a transition of transmission resonan ces, i. e., from incomplete transmission resonances in simple MB struc tures consisting of unidentical blocks, to complete transmission reson ances in comparatively complex MB structures (n greater than or equal to 4, n is the number of barriers). In simple unidentical block arrang ements in double- and triple-MB structures we can also obtain complete transmission by properly adjusting parameters of the building blocks according to k(y)-value (k(y), is the wave vector in y direction). Str ong suppression of the transmission and of the conductance is found in MB superlattices which are periodic arrangements of two different blo cks. The resonance splitting effect in finite MB superlattices is exam ined. It is confirmed that the rule (i.e., for n-barrier tunneling the splitting would be (n - 1)-fold) obtained in periodic electric superl attices can be extended to periodically arranged MB superlattices of i dentical blocks through which electrons with k(y) greater than or equa l to 0 tunnel, and it is no longer proper for electrons with k(y) < 0 to tunnel.