15jun5:00 pm6:00 pmAndreas HeinrichCenter for Quantum Nanoscience5:00 pm - 6:00 pm KST ZOOM Application
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
Date: June 15, 2020
Time: 17:00 -18:00
The Talk is provided by orginizers from Aalto University, Finland
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 . 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 . 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 .
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 . 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.
 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)
 Reina Gálvez, C. Wolf, F. Delgado, and N. Lorente, Physical Review B 100, 035411 (2019)
 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)
 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)
(Monday) 5:00 pm - 6:00 pm KST