Sustained charge-echo entanglement in a two charge qubits under random telegraph noise
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Sustained charge-echo entanglement in a two charge qubits under random telegraph noise A. Ayachi1
· W. Ben Chouikha1 · S. Jaziri1,2
Received: 5 March 2020 / Accepted: 11 August 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract The echo signal influence in restoring the coherence lost due to a random telegraph noise (RTN) in a double quantum dot has been theoretically investigated. In this paper, we discuss the RTN effects according to two different protocols manipulations: free induction and echo signal. The time evolution of the coherence factor for both protocols is evaluated employing the equation of motion approach. The time dependence of both fidelity and purity is numerically assessed as well. Our results unveil an enhancement in the entangled states lifetime and how the effects of the RTN, ubiquitous to the solid-state devises, can be counteracted. Furthermore, applying charge-echo stretches the coherence time. Our results exhibit an improvement by 4 times of the coherence time, proving the echo signal efficiency. It is worth mentioning that our analysis is also applicable to other solid-state devices and helpful for further understanding the open quantum systems dynamics. Keywords Entanglement · Decoherence · Random telegraph noise · Echo signal
1 Introduction Proposals aiming to implement a scalable quantum computer, based on semiconductor quantum dots, evince the great promise of these devices [1–3]. Particularly, using the electron charge degrees of freedom in a double quantum dots has the potential for high speed operations for quantum information processing [4–7]. Despite their large-scale integration, charge qubits usually suffer from short coherence time due to unavoidable interaction with the surrounding and fluctuating environment. The
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A. Ayachi [email protected]
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Laboratoire de Physique de la Matière Condensée, Faculté des Sciences de Tunis, Université de Tunis el Manar, campus universitaire de tunis, 2092 Tunis, Tunisia
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Laboratoire de Physique des Matériaux: Structure et Propriétés, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Zarzouna, Bizerte, Tunisia 0123456789().: V,-vol
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coupling to environment leads to decoherence which represents a drawback to their use in quantum information [8,9]. Thus, it is important to improve the coherent control and to increase the coherence time for charge qubits. This fact has incited a large effort intended on one side to understand and to depict the mechanisms that give rise to decoherence and on the other side to proceed to eliminate them and eventually improve the charge qubits coherence properties [10–15]. In connection with this context, quantum coherence is a central issue in quantum information processing. Unfortunately, coherent nano-devices are inevitably coupled to fluctuations due to the solid-state environment. These fluctuations destroy any initially prepared quantum states superposition and give rise to decoherence. One representative exam
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