Electrically Driven Spin Resonance of 4f Electrons in a Single Atom on a Surface

TL;DR

This study demonstrates electrically driven spin resonance of a single lanthanide atom's 4f electrons using a tailored spin structure on a surface, achieving enhanced coherence and control for quantum applications.

Contribution

It introduces a novel method to manipulate and detect 4f electron spins in single lanthanide atoms via a coupled structure with 3d electrons, improving coherence and control.

Findings

Five-fold increase in spin relaxation time for erbium 4f electrons

Two-fold increase in driving efficiency compared to 3d electrons

All-electric coherent control of highly protected spin states

Abstract

A pivotal challenge in quantum technologies lies in reconciling long coherence times with efficient manipulation of the quantum states of a system. Lanthanide atoms, with their well-localized 4f electrons, emerge as a promising solution to this dilemma if provided with a rational design for manipulation and detection. Here we construct tailored spin structures to perform electron spin resonance on a single lanthanide atom using a scanning tunneling microscope. A magnetically coupled structure made of an erbium and a titanium atom enables us to both drive the erbium's 4f electron spins and indirectly probe them through the titanium's 3d electrons. In this coupled configuration, the erbium spin states exhibit a five-fold increase in the spin relaxation time and a two-fold increase in the driving efficiency compared to the 3d electron counterparts. Our work provides a new approach to accessing highly protected spin states, enabling their coherent control in an all-electric fashion.