Electrical Spin Pumping in Exchange-coupled Molecules

TL;DR

This paper demonstrates a novel all-electrical method for remote initialization of electron spins in single molecules using exchange interactions and spin-polarized tunneling, advancing quantum information processing.

Contribution

It introduces a new approach for remote spin control in molecules via exchange coupling and spin-polarized currents, enabling reliable qubit initialization.

Findings

Exchange interaction enables angular momentum transfer between molecules.

Remote spin state control achieved through spin-polarized tunneling current.

Method is broadly applicable to various spin-based quantum systems.

Abstract

Electron spins in single molecules are a promising platform for quantum information processing. However, their practical implementation as qubits requires reliable control at the single-entity level, including an efficient state initialization. Here, we demonstrate the remote, all-electrical initialization of the electron spin in single molecules: Using electron spin resonance scanning tunneling microscopy, we investigate coupled pairs of S=1/2 molecules (Fe-FePc), where one molecule serves as a readout and pumping unit for the neighboring one. We show that the exchange interaction between them enables angular momentum transfer, which allows for the control of the remote spin state via the direction and magnitude of the spin-polarized tunneling current and the exchange coupling strength. These results establish a general, all-electrical approach for remote spin initialization that is readily transferable to a wide range of spin-based quantum architectures.