Robust entanglement of an asymmetric quantum dot molecular system in a Josephson junction

TL;DR

This paper presents a method to generate and control robust entanglement in an asymmetric quantum dot system within a Josephson junction, using tunable parameters and engineered reservoirs for high-quality quantum information processing.

Contribution

It introduces a protocol employing asymmetric quantum dots and reservoir engineering to achieve and maintain near-unit entanglement in a voltage-controlled Josephson junction.

Findings

Perfect entanglement achieved in asymmetric structures.

Entanglement remains near-unit with increasing bias voltage.

Tunable parameters allow arbitrary entanglement control.

Abstract

We demonstrate how robust entanglement of quantum dot molecular system in a voltage controlled junction can be generated. To improve the quantum information characteristics of this system, we propose an applicable protocol which contains the implementation of asymmetric quantum dots as well as engineering reservoirs. Quantum dots with tunable energy barriers can provide asymmetric coupling coefficients which can be tuned by gap voltages. Also by engineering reservoirs, superconductors can be used as leads in a biased-voltage junction. The high-controllability characteristics of system supplies the arbitrary entanglement by tuning the controlling parameters. Significantly in concurrence-voltage characteristics, perfect entanglement can be achieved in an asymmetric structure and it can be kept with near-unit magnitude in response to bias voltage increasing.