Spin entangled two-particle dark state in quantum transport through coupled quantum dots

TL;DR

This paper proposes a quantum transport setup with coupled quantum dots that can generate and verify spin-entangled two-electron dark states, highlighting their unique transport properties and entanglement measures.

Contribution

It introduces a novel quantum dot configuration capable of creating spatially separated spin-entangled dark states and analyzes their properties without reservoir coupling.

Findings

Existence of a spin-entangled dark state confirmed

Enhanced Fano factor for singlet dark state observed

High concurrence indicating strong entanglement

Abstract

We present a transport setup of coupled quantum dots that enables the creation of spatially separated spin-entangled two-electron dark states. We prove the existence of an entangled transport dark state by investigating the system Hamiltonian without coupling to the electronic reservoirs. In the transport regime the entangled dark state which corresponds to a singlet has a strongly enhanced Fano factor compared to the dark state which corresponds to a mixture of the triplet states. Furthermore we calculate the concurrence of the occupying electrons to show the degree of entanglement in the transport regime.