Charge qubit entanglement in double quantum dots

TL;DR

This paper investigates how entanglement of charge qubits in double quantum dots can be generated, controlled, and detected, revealing a maximum at specific interaction strengths and tunnel couplings.

Contribution

It provides a detailed analysis of entanglement behavior in double quantum dots using exact diagonalization, highlighting control mechanisms via gate voltages.

Findings

Entanglement can be efficiently generated and controlled by sidegate voltages.

Negativity shows a maximum at intermediate interaction strength for large tunnel coupling.

Entanglement detection methods are described.

Abstract

We study entanglement of charge qubits in a vertical tunnel-coupled double quantum dot containing two interacting electrons. Exact diagonalization is used to compute the negativity characterizing entanglement. We find that entanglement can be efficiently generated and controlled by sidegate voltages, and describe how it can be detected. For large enough tunnel coupling, the negativity shows a pronounced maximum at an intermediate interaction strength within the Wigner molecule regime.