  The formation of persistent charge currents in mesoscopic systems remains an
interesting and actual topic of condensed matter research. Here, we analyze the
formation of spontaneous arising persistent currents of charged fermions in
2-dimensional electron-hole ribbons on the top and bottom of a 3-dimensional
topological insulator. In such a device the two-dimensional Dirac fermions with
opposite chiralities are spatially separated that allows these currents to flow
in the opposite directions without compensating each other. The nature of this
phenomenon is based on the interference of the quasiparticle quantum waves
which are scattered with asymmetric scattering phases at the lateral n-p chiral
junction and then reflected back by the external boundaries of the ribbon. As a
result quasiparticles in the ribbon are shown to be in unified electron-hole
quantum states carrying the persistent current.
