Applied Physics and Material Science Graduate Seminar
Speaker: A.J. Heinrich, Center for Quantum Nanoscience, Institute for Basic Science (IBS) and, Department of Physics, Ewha Womans University.
Abstract
There is a strong international research effort in the area of quantum information science. Here, the concepts of quantum coherence, superposition and entanglement of quantum states are exploited. These concepts were originally shown with photons as well as atoms and ions in vacuum traps. Over the past two decades, many advances at studying such quantum coherence in solid-state and molecular architectures have evolved [1].
In this talk we will focus on my own research efforts in Scanning Tunneling Microscopy (STM). STM enables the study of surfaces with atomic-scale spatial resolution and offers the ability to study individual atoms and molecules on surfaces. Here at Ewha, we have one of the world’s best facilities for such studies. STM can also be used to move atoms with atomic-scale precision, which enables us to build engineered nanostructures where each atom is in the exactly correct place.
In order to study qubits with STM, we recently learned how to combine STM with electron spin resonance [2,3]. Spin resonance gives us the means to quantum-coherently control an individual atomic or molecular spin on a surface. Using short pulses of microwave radiation further enables us to perform qubit rotations and learn about the quantum coherence times of our spins [4]. Finally, we will finish with unpublished results on multi-qubit operations with spins on surfaces.
1. Andreas J. Heinrich, William D. Oliver, Lieven M. K. Vandersypen, Arzhang Ardavan, Roberta Sessoli, Daniel Loss, Ania Bleszynski Jayich, Joaquin Fernandez-Rossier, Arne Laucht, Andrea Morello, “Quantum-coherent nanoscience”, Nature Nanotechnology, 16, 1318-1329 (2021).
2. 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).
3. Yi Chen, Yujeong Bae, Andreas Heinrich, “Harnessing the Quantum Behavior of Spins on Surfaces”, Advanced Materials 2022, 2107534 (2022).
4. Kai Yang, William Paul, Soo-Hyon Phark, Philip Willke, Yujeong Bae, Taeyoung Choi, Taner Esat, Arzhang Ardavan, Andreas J. Heinrich, and Christopher P. Lutz, “Coherent spin manipulation of individual atoms on a surface”, Science 366, 509 (2019).
Support from Institute for Basic Science (IBS-R027-D1) is gratefully acknowledged.
Bio
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 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 member of the Korean and German
Physical Societies as well as a fellow of the American Physical Society and the
American Association for the Advancement of Science.
