NATURE OF EIGENSTATES IN A MESOSCOPIC RING COUPLED TO A SIDE BRANCH

We formalize the parity effect of a multichannel ring coupled to a sid e branch using the tight-binding model. We find that the tight-binding model gives slightly different results from the continuum model. We a lso show that some states of the system can be nonmagnetic. In the mul tichannel ring coupled to a side branch, the persistent current in the ring does not change sign, over gigantic fluctuations in N (the numbe r of particles in the ring).