2024/07/08 by Patra, Moumita, Agarwalla, Bijay Kumar, Maiti, Santanu K.
#FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.2407.05830
When the degeneracies of the ring-Hamiltonian are removed by the asymmetric ring-to-electrodes configuration for an open quantum ring (OQR), the overall junction transmission function exhibits fano-type antiresonance, resulting a net circular current appears within the channel, that is the ring around the degenerate energy levels of the ring-Hamiltonian. We investigate the system size scaling properties of the channel conductance and the overall junction conductance of an OQR. Ballistic transport is the unhindered flow of a charge carrier within a conductor. Here we find beyond-ballistic transport near both the degenerate and non-degenerate eigenenergies of the ring-Hamiltonian, depending on the ring-to-lead configuration. This is a purely OQR phenomenon associated with the quantum interference effect between two counter-propagating electronic waves having nearly equal and opposite momenta. Thus there is no equivalent phenomenon in open quantum junctions with linear channel.