Entanglement between charge qubits induced by a common dissipative environment

TL;DR

This paper investigates how a common dissipative environment can induce entanglement between two charge qubits, revealing a non-monotonic relationship between entanglement and environmental coupling strength, with implications for quantum dot systems.

Contribution

It demonstrates the dual role of a common bosonic environment in both generating entanglement and causing decoherence in charge qubits, highlighting the non-monotonic behavior of entanglement.

Findings

Entanglement is induced by the common environment despite decoherence.

The concurrence exhibits a non-monotonic dependence on bath coupling strength.

Results are applied to charge qubits in double quantum dots.

Abstract

We study entanglement generation between two charge qubits due to the strong coupling with a common bosonic environment (Ohmic bath). The coupling to the boson bath is a source of both quantum noise (leading to decoherence) and an indirect interaction between qubits. As a result, two effects compete as a function of the coupling strength with the bath: entanglement generation and charge localization induced by the bath. These two competing effects lead to a non-monotonic behavior of the concurrence as a function of the coupling strength with the bath. As an application, we present results for charge qubits based on double quantum dots.