Photogalvanic effect in a quantum ring with attached conductors

The electric current induced by the circularly polarized radiation in a quantum ring with two arbitrarily attached one-dimensional conductors has been investigated. Contacts between the ring and conductors are modeled using the theory of zero-range potentials. The expression for the electron transmission coefficient is derived taking into account the inelastic interaction with the radiation. It is shown that two mechanisms of photocurrent generation occur in this system. The first one is caused by the difference in amplitudes of the zero-range potential in contact points, while the second one is caused by the asymmetry in the arrangement of contacts on the ring. The dependence of the photocurrent on the chemical potential of electrons, radiation frequency, arrangement of contacts, amplitudes of the zero-range potential, and magnetic flux through the ring is investigated.