Conductance in a narrow constriction threaded by an impenetrable magnetic flux tube

Abstract

The conductance G in a narrow constriction and its dependence on the Fermi energy and on the transverse position of an impenetrable magnetic flux tube is studied. G exhibits oscillatory-like behavior as the transverse position of the tube changes. When there are n propagating subbands, there are n - 1 minimums of G first (except for n = 1) and n minimums later when the Fermi energy grows. Both just below and just above the critical energy exhibiting n propagating subbands, minimums occur at tube,positions mW/n, where W is the transverse width of the constriction and 1 less than or equal to m less than or equal to n - 1.