Bistability in the Electric Current through a Quantum-Dot Capacitively Coupled to a Charge-Qubit

author

  • S. M. Tabatabaei Department of Applied Physics, Faculty of Physics, University of Shahid Beheshti, Evin, Tehran, Islamic Republic of Iran
Abstract:

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.

Upgrade to premium to download articles

Sign up to access the full text

Already have an account?login

similar resources

Quantum current modeling in nano-transistors with a quantum dot

Carbon quantum dots (CQDs) serve as a new class of ‘zero dimensional’ nanomaterial’s in thecarbon class with sizes below 10 nm. As light emitting nanocrystals, QDs are assembled from semiconductormaterials, from the elements in the periodic groups of II-VI, III-V or IV-VI, mainly thanks to impacts of quantum confinement QDs have unique optical properties such as brighter, highly pho...

full text

Correlated Coulomb Drag in Capacitively Coupled Quantum-Dot Structures.

We study theoretically Coulomb drag in capacitively coupled quantum dots (CQDs)-a bias-driven dot coupled to an unbiased dot where transport is due to Coulomb mediated energy transfer drag. To this end, we introduce a master-equation approach that accounts for higher-order tunneling (cotunneling) processes as well as energy-dependent lead couplings, and identify a mesoscopic Coulomb drag mechan...

full text

Josephson current through a quantum dot coupled to a molecular magnet

Josephson currents are carried by sharp Andreev states within the superconducting energy gap. We theoretically study the electronic transport of a magnetically tunable nanoscale junction consisting of a quantum dot connected to two superconducting leads and coupled to the spin of a molecular magnet. The exchange interaction between the molecular magnet and the quantum dot modifies the Andreev s...

full text

Effect of asymmetric quantum dot rings in electron transport through a quantum wire

The electronic conductance at zero temperature through a quantum wire with side-connected asymmetric quantum ring (as a scatter system) is theoretically studied using the non-interacting Hamiltonian Anderson tunneling method. In this paper we concentrate on the configuration of the quantum dot rings. We show that the asymmetric structure of QD-scatter system strongly influences the amplitude an...

full text

Effect of asymmetric quantum dot rings in electron transport through a quantum wire

The electronic conductance at zero temperature through a quantum wire with side-connected asymmetric quantum ring (as a scatter system) is theoretically studied using the non-interacting Hamiltonian Anderson tunneling method. In this paper we concentrate on the configuration of the quantum dot rings. We show that the asymmetric structure of QD-scatter system strongly influences the amplitude an...

full text

My Resources

Save resource for easier access later

Save to my library Already added to my library

{@ msg_add @}


Journal title

volume 29  issue 1

pages  79- 85

publication date 2018-01-30

By following a journal you will be notified via email when a new issue of this journal is published.

Hosted on Doprax cloud platform doprax.com

copyright © 2015-2023