The effect of higher order hopping integrals on persistent current of a mesoscopic normal metal ring
For the last few decades, many probes have been concentrated on magnetic response of mesoscopic normal metal rings and have been obtained many exotic results as a consequence of phase coherence of the electrons in the mesoscopic scale.
We have used the tight-binding model to describe a mesoscopic normal metal ring.
We have taken the hopping integral between any two sites i and j.
We have considered a ring which consists of 100 sites with even or odd number of electrons.
By using the Hamiltonian in T.B model, we have evaluated the total persistent current for the mesoscopic normal metal ring.
We have presented the diagrams of total persistent current versus the magnetic flux that show saw-tooth behavior which are diamagnetic for even or odd number of electrons.
We have also obtained the difference between persistent currents of various successive order hopping integrals versus the magnetic flux for even or odd number of electrons.
Whenever this difference approximately approaches to zero, we can neglect the higher order hopping integrals in calculation of the electronic physical properties of the system and as a result,the enough number of hopping integrals is intensively depends on the number of the electrons in the ring.