Growth of Self-Assembled Mn-Atomic Chains on Pb-c(8×4) on Si(100) Substrate

Nitin Kumar^1*, Guan-Yu Chen¹, Shiu-Chun Chen¹, Rovi Angelo B. Villaos³, Gennevieve Macam³, Chia-Hsiu Hsu³, Feng-Chuan Chuang^1,3,4, Pin-Jui Hsu^1,2

¹Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
²Center of Quantum Technology, National Tsing Hua University, Hsinchu 30013, Taiwan
³Department of Physics, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
⁴Physics Division, National Center for Theoretical Sciences, Hsinchu 30013, Taiwan

* Presenter:Nitin Kumar, email:itsnitin95@gmail.com

Material realization of topological superconductors (TSCs) is a key step towards the development of the Majorana based qubits for quantum computers. A hybrid system of a superconductor having 1D chain of magnetic atoms on top of it is a propitious system for producing localized topological superconductivity that may host Majorana Bound States (MBSs). We grow a hybrid system having 1D chains of Mn atoms on the 2D film of Pb-c(8×4) on Si(100) substrate. Surface coverage of Pb-c(8×4) on Si(100) is equivalent to 0.75 ML. A 77K, scanning tunneling microscope (STM) has been used to study the growth of the c(8×4) phase of Pb on Si(100), in which the parallelly running chains of buckled Pb-rings are formed along the [110] direction. We observe that the distribution of Mn atoms on 2D Pb film is ordered, uniform and monoatomic. Mn atom can be absorbed either on the buckling bridge site between two Pb-rings or at the center of the Pb-ring, but these two adsorption sites do not co-exist. Based on our STM investigation combined with DFT calculation, we propose atomic models for both kinds of Mn-absorptions and the simulated STM images are in line with experimental results.

Keywords: Scanning tunneling microscopy, Topological superconductor, Majorana bound states