Spin-entangled currents created by a triple quantum dot

TL;DR

This paper proposes a triple quantum dot setup that generates and maintains spin-entangled electron currents by leveraging singlet ground states and secondary dots to preserve entanglement during transport.

Contribution

It introduces a novel quantum dot configuration that efficiently produces spatially separated spin-entangled electrons with a mechanism to preserve entanglement during extraction.

Findings

Enables generation of spin-entangled electron currents.

Uses secondary dots to preserve entanglement during transport.

Resonant enhancement of joint electron transport.

Abstract

We propose a simple setup of three coupled quantum dots in the Coulomb blockade regime as a source for spatially separated currents of spin-entangled electrons. The entanglement originates from the singlet ground state of a quantum dot with an even number of electrons. To preserve the entanglement of the electron pair during its extraction to the drain leads, the electrons are transported through secondary dots. This prevents one-electron transport by energy mismatch, while joint transport is resonantly enhanced by conservation of the total two-electron energy.