Non-equilibrium Entanglement and Noise in Coupled Qubits

TL;DR

This paper investigates charge entanglement and quantum noise in coupled quantum dots, revealing how entanglement can be controlled and detected through transport properties and noise spectra.

Contribution

It provides a detailed analysis of entanglement behavior under equilibrium and non-equilibrium conditions, introducing noise spectra as a tool for entanglement detection.

Findings

Entanglement exhibits a switching threshold in transport regimes.

Quantum Zeno effect and energy gaps suppress tunneling and influence entanglement.

Current noise spectra correlate with entanglement in transport experiments.

Abstract

We study charge entanglement in two Coulomb-coupled double quantum dots in thermal equilibrium and under stationary non-equilibrium transport conditions. In the transport regime, the entanglement exhibits a clear switching threshold and various limits due to suppression of tunneling by Quantum Zeno localisation or by an interaction induced energy gap. We also calculate quantum noise spectra and discuss the inter-dot current correlation as an indicator of the entanglement in transport experiments.