“School of Physics”

Back to Papers Home
Back to Papers of School of Physics

Paper   IPM / P / 17975
School of Physics
  Title:   Twist-Angle Tuning of Electronic Structure in Two-Dimensional Dirac Nodal Line Semimetal Au$_2$Ge on Au(111)
  Author(s): 
1.  Q. Tian
2.  M. Bagheri Tagani
3.  S. Izadi Vishkayi
4.  Ch. Zhang
5.  B. Li
6.  L. Zhang
7.  L. Jing Yin
8.  Y. Tian
9.  L. Zhang
10.  Zh. Qin
  Status:   Published
  Journal: ACS Nano
  No.:  12
  Vol.:  18
  Year:  2024
  Pages:   9011-9018
  Supported by:  IPM
  Abstract:
Topological semimetals have emerged as quantum materials including Dirac, Weyl, and nodal line semimetals, and so on. Dirac nodal line (DNL) semimetals possess topologically nontrivial bands crossing along a line or a loop and are considered precursor states for other types of semimetals. Here, we combine scanning tunneling microscopy/spectroscopy (STM/S) measurements and density functional theory (DFT) calculations to investigate a twist angle tuning of electronic structure in two-dimensional DNL semimetal Au$_2$Ge. Theoretical calculations show that two bands of Au$_2$Ge touch each other in $\Gamma$-M and $\Gamma$-K paths, forming a DNL. A significant transition of electronic structure occurs by tuning the twist angle from 30 to 24-degree between monolayer Au$_2$Ge and Au(111), as confirmed by STS measurements and DFT calculations. The disappearing of DNL state is a direct consequence of symmetry breaking.

Download TeX format
back to top
scroll left or right