Generation of entanglement between quantum dot molecule with the presence of phonon effects in a voltage-controlled junction

TL;DR

This paper explores how phonon interactions influence entanglement generation in a quantum dot molecule within a voltage-controlled junction, demonstrating methods to enhance and sustain entanglement despite thermal effects.

Contribution

It introduces an asymmetric coupling protocol and bias voltage control to generate and maintain robust entanglement in a phonon-influenced quantum dot system.

Findings

Entanglement can be periodically revived with oscillating bias voltage.

Thermal entanglement degradation and revival are affected by phonon decoherence.

Higher phonon coupling can lead to larger entanglement revival values.

Abstract

We investigate the generation of entanglement through a quantum dot molecule under the influence of vibrational phonon modes in a bias voltage junction. The molecular quantum dot system is realized by coupled quantum dots inside a suspended carbon nanotube. We consider the dynamical entanglement as a function of bias voltage and temperature by taking into account the electron-phonon interaction. In order to generate the robust entanglement between quantum dots and preserve it to reach the maximal achievable amount steadily, we introduce an asymmetric coupling protocol and apply the easy tunable bias voltage-driven field. For an oscillating bias voltage, the time-varying entanglement can periodically reach the maximum revival. In thermal entanglement dynamics, the phenomena of thermal entanglement degradation and thermal entanglement revival are observed which are intensively affected by the strength of phonon decoherence. The revival of entanglement shows a larger value for a higher phonon coupling.