[原分所演講] IAMS Special Seminar (November 5, Prof. Han Woong Yeom)
Special Seminar
Time: 10:00-11:00, November 5, 2018
Location: Dr. Poe Lecture Hall, IAMS, Academia Sinica (NTU Campus)
Title: Emerging Topology of Atomic Wires toward Topological Informatics
Speaker: Dr. Han Woong Yeom (Director, Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, Korea) (CV attached)
Post Seminar Discussion: Restructuring of South Korean Science
Time: 11:00-12:00, November 5, 2018
Abstract
Emerging Topology of Atomic Wires toward Topological Informatics
Han Woong Yeom
Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, Korea
Department of Physics, POSTECH, Pohang, Korea
Self-assembled atomic wires have attracted substantial interest in last decade due to their potential to reveal new physics of 1D electrons and as possible components of atomic scale device architecture. A few interesting issues have been discussed so far such as charge density waves (CDW) [1], non-Fermi liquid behavior, and giant Rashba splitting [2]. We have contributed substantially to initiate and establish this field of research during last 20 years. In this talk, we will review our recent work on the topological nature of the CDW ground state of indium atomic wires on Si(111) [1, 3], which leads us to beautiful topological physics and hopefully new technology. In 2012, we succeeded in directly observing individual soliton excitations within the CDW band gap [4]. It did not take a long time to realize that these solitons manifest the unusual topological structure of the CDW state [5]. That is, each In atomic wire is composed of double Peierls chains, which yield uniquely four degenerate CDW ground states and corresponds to the first materials realization of a Z4topological insulator [5]. This unique topology endows chirality to its edge states, the solitons, which is equivalent to the chiral edge current of higher dimensional topological insulators [5]. We thus for the first time clarified the 1D chiral edge state of a 1D topological insulator and discovered the first topological insulator beyond the Z and Z2 topology. The exciting prospect of utilizing chiral solitons for topologically-protected multi-level informatics, which we would call ‘chiral solitonics,’ is introduced [6]. 20 years may be long or not too long to discover new physics, chiral solitons and Z4 topological insulator and to coin new concept, solitonics.
REFERENCES
- Han Woong Yeom et al., Phys. Rev. Lett. 82, 4898 (1999).
- Jewook Park et al., Phys. Rev. Lett. 110, 036801 (2013).
- J. R. Ahn, J. H. Byun, H. Koh, E. Rotenberg, S. D. Kevan, and H. W. Yeom, Phys. Rev. Lett. 93, 106401 (2004).
- Tae-Hwan Kim and Han Woong Yeom, Phys. Rev. Lett. 109, 246802 (2012).
- Sang-Mo Chun, Sung Hoon Lee, Tae-Hwan Ki, and Han Woong Yeom, Science, 350, 182 (2015).
- Tae-Hwan Ki, Sang-Mo Chun, and Han Woong Yeom, Nature Phys. 13, 444 (2017).