Visualizing Quasiparticle Interference in Monolayer (√3×√3)R30°-Ag₂Sn Binary Alloy by Scanning Tunneling Microscopy and Spectroscopy

Guan-Yu Chen^1*, Yi-Hao Zhuang¹, Jia-Ru Chen¹, Pin-Jui Hsu¹

¹Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Guan-Yu Chen, email:xxx2736338@gmail.com

We investigate the electronic structure of Ag(111)(√3×√3)R30°-Ag₂Sn surface alloy by quasiparticle interference (QPI) mapping with low-temperature scanning tunneling microscopy (STM) and spectroscopy (STS). From STS results, we observe two signals of surface bands, one in the occupied range with a step-like feature (sp_z) and the other in the unoccupied range with a Rashba-split-band singularity peak (p_xp_y,m_j=1/2). With QPI mapping, we systematically assign scattering vectors to each surface band and compare with ARPES measurements, depicting a more detailed structure of Rashba-type system.

Keywords: Rashba effect, spin-orbit coupling, scanning tunneling microscopy, scanning tunneling spectroscopy, quasiparticle interference