The MCQST Colloquium Series features interdisciplinary talks given by visiting international speakers. The monthly colloquium covers topics spanning all MCQST research units and will be broadcast live via Zoom for audiences worldwide. The main goal of the series is to create the framework for idea exchange, to strengthen links with QST leading groups worldwide, as well as to act as an integral part of the local educational environment.

MCQST Special Colloquium: Andreas Heinrich

We are excited to invite you to the colloquium talk by Andreas Heinrich (Ewha University). You can join us in-person at the TUM Physics-Department, Hörsaal 3.

Talk Information

Towards Quantum Computing with Spins on Surfaces

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 quantum-coherent experiments 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 Finally, we will finish with unpublished results on multi-qubit operations with spins on surfaces.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.

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 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