Electrically driven spin resonance of 4f electrons in a single atom on a surface

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. The erbium spin states exhibit an extended spin relaxation time and a higher driving efficiency compared to 3d atoms with spin ½ in similarly coupled structures. Our work provides a new approach to accessing highly protected spin states, enabling their coherent control in an all-electric fashion.

Decoupling the spins of a quantum system from environmental noises is the key to avoid decoherence. At the same time, electrical control over the spin state is a highly desirable feature for integration with present devices. Herein, Reale et al. demonstrate all-electrical spin drive and read-out of an individual Er atom with well decoupled 4f electrons.