Speaker: Professor Andreas J. Heinrich
Affiliation: Director, Center for Quantum Nanoscience, Institute for Basic Science, Seoul Department of Physics, Ewha Womans University, Seoul, Korea
Host: Assistant Professor Lu Jiong
Location: Click HERE for directions
Abstract Details: The scanning tunneling microscope is an amazing tool because of its atomic-scale spatial resolution. This can be combined with the use of low temperatures, culminating in precise atom manipulation and spectroscopy with microvolt energy resolution. In this talk we will apply these techniques to the investigation of the quantum spin properties of magnetic atoms sitting on thin insulating films.
We will start our exploration with the understanding of the quantum spin states (also called the magnetic states) of these adsorbates. To measure these states, we combined scanning tunneling with x-ray absorption spectroscopy and found amazing agreement of those vastly different techniques (Science 2014, PRL 2015).
Next, we will investigate the lifetimes of excited states. Surprisingly, we find lifetimes that vary from nanoseconds to hours, a truly amazing consequence of the quantum states of different adsorbates.
Finally, we will explore the superposition of quantum states which is inherent to spin resonance techniques. We recently demonstrated the use of electron spin resonance on single Fe atoms on MgO (Science 2015). This technique combines the power of STM of atomic-scale spectroscopy with the unprecedented energy resolution of spin resonance techniques, which is about 10,000 times better than normal spectroscopy.
About the Speaker: Heinrich is a world-leading researcher in the field of quantum measurements on the atomic-scale in solids. He pioneered spin excitation and single-atom spin resonance spectroscopy with scanning tunneling microscopes – methods that have provided high-resolution access to the quantum states of atoms and nanostructures on surfaces. He has a track record of outstanding publications and invited talks and has established a strong network of global collaborations. As a consequence, Heinrich’s work has received extensive media coverage worldwide.
Heinrich received his Masters (Diplom) degree in 1994 and his doctorate in 1998 in physics at Georg-August University in Goettingen, Germany. Heinrich then spent 18 years in IBM Research, which uniquely positioned him to bridge the needs of industrial research and the academic world. This unique environment gave Heinrich extensive experience in presenting to corporate and political leaders, including the president of Israel and the IBM Board of Directors. Heinrich became a distinguished professor of Ewha Womans University in August 2016 and started the Center for Quantum Nanoscience (QNS) of the Institute for Basic Science (IBS) in January 2017. Under his leadership, QNS focuses on exploring the quantum properties of atoms and molecules on clean surfaces and interfaces with a long-term goal of quantum sensing and quantum computation in such systems. Heinrich is a fellow of the American Physical Society and the American Association for the Advancement of Sciences and a member of the German Physical Society and the Korean Physical Society.