Transport Properties of Quantum Interference Devices the Role of the Andreev Bound States

Quantum transport characteristic of a mesoscopic systems under the
effect of Coulomb blocked and magnetic field are studied. This system is
modeled as two semiconductor quantum dots which are coupled to a
superconducting lead via quantum point contacts. The Josephson current
density has been obtained in terms of the Andreev reflection amplitude. This
Andreev reflection amplitude was deduced by solving the Bogoliubov – de
Gennes (BdG) equation, describing the electron transport through the present
studied junction. Numerical calculation of the obtained current density has
been performed. The dependence of the current density on phase angle φ shows
a periodic variation. While the oscillation features of the current density with
the magnetic field are predicted to be due to quantum interference of electron
waves. So such junction can be operated as a quantum interference tuner which
may be valuable for nanotechnology.