Han-woong Yeom

Academic Affiliation: CALDES, IBS & POSTECH

Title: Nano-tsunami along atomic chains and domain walls for robust informatics

Abstract:

Storing and manipulating information in robust and dissipationless ways is of prime interest in various fields of science and technology. Using topologically protected local excitations, form examples, skyrmions and Majorana fermions, such robust informatics may be realized. This talk reviews our own approach to this issue, which deals with new types of solitons in electronic systems. We will first discuss atomic chains formed on silicon surfaces in charge-density-wave ground states and their solitons. We recently identified individual electronic solitons in indium atomic chains on a Si(111) surface and, more recently, in silicon chains on stepped silicon surfaces . Due to their unique structures, they represent unprecedented topological systems of Z₄ [1] and Z₃ [2], respectively, with three and two distinct solitons. These solitons can store, deliver, and operate multi-level information bits, which are protected topologically [3]. We further demonstrate solitons with higher multiplicity can be formed as a form of mobile kinks [4] along the charge-density-wave domain walls on a 2D material of 1T-TaS₂ [5]. Thus, the possibility of multi-level and topologically protected information processing with solitons, or solitonics, is well demonstrated. Further studies on soliton-defect, soliton-soliton, and soliton-excitation interactions are exciting for soliton applications.

References:

[1] S. M. Cheon, S. H. Lee, T. H. Kim, and H. W. Yeom, Science 350, 182 (2015).

[2] J. W. Park, E. Do, J. S. Shin, S. K. Song, O. P. Jelinek, and H. W. Yeom, Nature Nanotechnology 17, 244 (2022).

[3] S. M. Cheon, T. H. Kim, and H. W. Yeom, Nature Physics 13, 444 (2017).

[4] J. W. Lee, J. W. Park, and H. W. Yeom, PRL, under review (2022).

[5] D. Cho, G. Gye, J. Lee, S. H. Lee, L. Wnag, S-W. Cheong, and H. W. Yeom, Nature Commun. 8, 392 (2017)

Han Woong Yeom^1,2

¹Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang 37673, Korea.

²Department of Physics, POSTECH, Pohang 37673, Korea.