Upcoming Talks and Events:

Andreas Heinrich

Date: June 15, 2020

Time: 17:00 -18:00

The Talk is provided by orginizers from Aalto University, Finland

Click here to register >>

Virtual Talk – Electron Spin Resonance of single atoms on a surface observed with STM

Scanning Tunneling Microscopy (STM) can be combined with electron spin resonance [1]. The major advantage of spin resonance is the fact that the energy resolution is independent of the temperature and thus can be much higher than a Fermi-function limited spectroscopy technique such as STM tunneling. In ESR STM we apply a microwave-frequency electric field to the STM tunnel junction and convert this AC electric field into a driving field for the ESR [2]. We find an energy resolution in ESR STM, which is about 10,000 times better than low-temperature STM.

Here we will focus on two examples: Fe and Ti atoms on MgO on Ag(100). Fe on MgO has a spin of S=2 with a strong out-of-plane easy-axis magnetic anisotropy. ESR active Fe atoms can be used to measure the local magnetic field very precisely and with atomic-scale spatial resolution. We will use this to measure the magnetic field emanating from a stable single-atom magnet nearby: Ho on MgO [3].

Ti atoms on MgO are an S=1/2 electron system (when a single Hydrogen is attached) with an interesting nuclear spin system, consisting of several isotopes (I=0, I=5/2 and I=7/2). ESR STM can measure the hyperfine interaction of the electron spin with the nuclear spin of the Ti atom [4]. The hyperfine interaction is a sensitive measure of the local bonding geometry.

ESR STM is just in its infancy with many groups joining this research effort.

Support from Institute for Basic Science (IBS-R027-D1) is gratefully acknowledged.

References:

[1] Susanne Baumann, William Paul, Taeyoung Choi, Christopher P. Lutz, Arzhang Ardavan, Andreas J. Heinrich, “Electron Paramagnetic Resonance of Individual Atoms on a Surface”, Science 350, 417 (2015)
[2] Reina Gálvez, C. Wolf, F. Delgado, and N. Lorente, Physical Review B 100, 035411 (2019)
[3] Fabio Donati, S Rusponi, Sebastian Stepanow, C Wäckerlin, Aparajita Singha, Luca Persichetti, R Baltic, K Diller, Francois Patthey, E Fernandes, Jan Dreiser, Željko Šljivančanin, K Kummer, Corneliu Nistor, Pietro Gambardella, Harald Brune, Science 352, 318 (2016)
[4] Philip Willke, Yujeong Bae, Kai Yang, Jose L. Lado, Alejandro Ferrón, Taeyoung Choi, Arzhang Ardavan, Joaquín Fernández-Rossier, Andreas J. Heinrich and Christopher P. Lutz, “Hyperfine interaction of individual atoms on a surface”, Science 362, 336 (2018)

Virtual Workshop on Scanning Probe Microscopy

Date: June 18, 2020

Time: 9:00 – 13:00 CEST (16:00 – 20:00 KST)

Location: ZOOM

Virtual SPM is a free online workshop on recent advances in scanning probe techniques, in particular low-temperature UHV scanning tunneling microscopy and atomic force microscopy.

With three invited talks, discussion time and a live poster session to provide further opportunity to share ideas and results, we hope this event will bring the community together to discuss the latest advances and keep sharing results despite the current lack of in-person conferences. Registration is open!
This workshop is organized with the support of the Virtual Science Forum, a platform that helps with the organization of online conferences.

To register on the Workshop, please, follow the link ->