%0 Journal Article %T Bistability in the Electric Current through a Quantum-Dot Capacitively Coupled to a Charge-Qubit %J Journal of Sciences, Islamic Republic of Iran %I University of Tehran %Z 1016-1104 %A Tabatabaei, S. M. %D 2018 %\ 01/30/2018 %V 29 %N 1 %P 79-85 %! Bistability in the Electric Current through a Quantum-Dot Capacitively Coupled to a Charge-Qubit %K Nonequilibrium green's function method %K Current bistability %K Perturbation theory %K Majorana fermion representation of spin operators %R 10.22059/jsciences.2018.64796 %X We investigate the electronic transport through a single-level quantum-dot which is capacitively coupled to a charge-qubit. By employing the method of nonequilibrium Green's functions, we calculate the electric current through quantum dot at finite bias voltages. The Green's functions and self-energies of the system are calculated perturbatively and self-consistently to the second order of interaction between the quantum-dot and the charge-qubit by employing the Majorana fermion representation for isospin operators of the qubit. Our results show that in the particle-hole symmetric situation, the electric current of the QD exhibits a unitary linear conductance at low bias voltage and at the higher bias voltage it has a nonlinear dependence on the bias voltage. Moreover, we find that at some appropriate parameter regimes, the current through the QD as a function of gate voltage, at a fixed bias voltage shows bistability. %U https://jsciences.ut.ac.ir/article_64796_f798121dc690cd5392a385fd6cf07e6e.pdf