CONTROL KNOBS TO DESIGN ATOMIC SCALE SPINTRONIC DEVICES

Individual spins are the ultimate fraction of magnetization which can process, store and sense bits of information. With the advent of the new century, there has been a relentless increment of the energy consumption in electronic devices, and modern society meets this challenge with a desperate effort to decrease the footprint of active elements and their activation voltage thresholds. In addition, governmental agencies and private stakeholders already consider quantum processing paramount actor in the progress of materials and environmental sciences. From this perspective, it follows that not far from now, technology will demand access to individual atomic or molecular quantum spins. Before this time comes, scientists must provide the means to control atomic scale quantum spins, and perform basic read and write operations with them.

             In this talk I will present the toolkit for the control of electronic spins developed in the last ten years at the SPM laboratory of INMA. Among them, I will discuss the interaction with a free electron gas [1,2], the magnetic exchange interaction with artificially designed environments [3,4] and the tunable magneto-crystalline anisotropy. Each case will be illustrated by real world examples (i.e., under UHV and cryogenic conditions), making use of three main experimental techniques: atomic manipulation, spin-polarized STM and high resolution tunneling spectroscopy. We will consider two types of the most obvious spin carriers at hand: transition metal adatoms and spin-split p-molecular orbitals in nanographenes [4].

[1] M. Moro-Lagares et al., Real Space Manifestations of Coherent Screening in Atomic Scale Kondo Lattices, Nat Commun 10, 2211 (2019).

[2] M. Moro-Lagares, et al., Quantifying the Leading Role of the Surface State in the Kondo Effect of Co/Ag(111), Physical Review B 97, 235442 (2018).

[3] D. Serrate, et al., Imaging and Manipulating the Spin Direction of Individual Atoms, Nature Nanotechnology 5, 350 (2010).

[4] J. Brede et al., Detecting the spin-polarization of edge states in graphene nanoribbons, submitted to Science (2022)