ELECTRONIC CONDUCTANCE OF A T-SHAPED WAVE-GUIDE IN LOCAL MAGNETIC-FIELD

A theoretical study of the electronic conductance of an electron waveg uide with a T-stub in local magnetic field is presented. The conductan ce as a function of Fermi energy and magnetoconductance of a T-stub wi th various dimensions are calculated. It is found that at low incident electron energies the conductance is hardly changed with the magnetic held. At high energies the magnetic field shifts the resonant peaks a nd enhances the transmission on the average. Oscillatory structures of the magnetoconductance present for a T-stub with larger area while sm ooth curves exist for a stub with smaller area. Intuitive interpretati ons are given in terms of magnetic induced quasibound states and antir esonant reflections. The possibility of a magnetically controlled meso scopic device is discussed.