## 8 Twistronics in Epitaxial Graphene on SiC  
So far, the materials for twistronics studies are dominated by transfer assembly of exfoliated graphene, mono- and bi-layer. Due to its great precision, the tear and stack method [25; 87; 88] of transfer assembly enables the successful fabrication of desired magic angle TBG devices. On the other hand, future application of twistronics would demand mass production of TBG based devices, and thus require more efficient and economically available method for the production of TBG materials. The epitaxial graphene on wide band semiconductor SiC stands out as a very promising candidate, due to its natural compatibility with the semiconductor industry. Therefore, more attention should be paid to SiC supported epitaxial graphene. (See Figure 9)  
Figure 8: Correlated insulating, superconducting state and quantum anomalous hall effect (QAHE) in ABC-trilayer graphene. (**a**) Longitudinal resistance versus bottom gate voltage and tap gate voltage. (**b**) \(\rho_{xx}\) and \(\rho_{yx}\) versus the magnetic field with \(D=-0.5\) V nm\({}^{-1}\). Inset: a zoomed-in plot of \(\rho_{yx}\) at a small magnetic field. (**c**) Color plot of the normalized resistance versus carrier density and temperature at \(D=-0.54\) V nm\({}^{-1}\). (**d**) Valley splitting versus the magnetic field for partially filled at a low Landau level (LL) factor \(n=0,\,1,\,2\). Panel (**a**) adapted with permission from Ref. [79], Copyright Nature Publishing Group 2019. Panel (**b**) adapted with permission from Ref. [80], Copyright Nature Publishing Group 2019. Panel (**c**) adapted with permission from Ref. [15], Copyright Nature Publishing Group 2020. Panel (**d**) adapted with permission from Ref. [81], Copyright American Physical Society 2019. As early as in 1974, [PERSON], et al. already reported the ring shape Low Energy Electron Diffraction (LEED) pattern on graphitized SiC(\(000\overline{1}\)) [93], which now we know is multi-layer graphene with rotational domains of varying orientations. [PERSON] et al. also observed many large and small domains with various periodicities at 6H-SiC(\(000\overline{1}\)) surfaces [94], which can be explained as moire patterns formed on two graphene layers with different twist angles. On the 4H-SiC(\(000\overline{1}\)) substrate, [PERSON], et al. reported that multilayer graphene grown on the carbon terminated SiC surface contains three rotational domains, rotated by the \(30\pm 2.2^{\circ}\) direction, characterized by LEED as shown in Figure 9a, and these rotational stacking faults could be largely tuned by the annealing temperature [89]. Since the pioneer work by the [PERSON] group in 2004 [95], lots of attention has been focused on the SiC(\(0001\)), i.e., Si terminated face, due to the high quality of the self-limited epitaxial graphene up to two layers. Meanwhile, many surface science studies, by means of auger electron spectroscopy (AES) [90; 96], XPS [97; 98; 99], LEEM [100], STM [101], etc., were carried out on the epitaxial graphene on the SiC(\(000\overline{1}\)), i.e., C terminated face. It was confirmed that the C-face could provide multilayer epitaxial graphene with a thickness up to 10 s of nanometers, as shown in Figure 9b. The precise number of layers could be determined in situ [102]. Additionally, the technique to control the thickness and domain size of C-face graphene has also been developed. [PERSON] et al. [91], [PERSON] et al. [103] and [PERSON] et al. [104] reported the Ar atmosphere annealing method that could provide micrometer sized single domains, as shown in Figure 9c. The epitaxial graphene on C-face SiC tends to exhibit a variety of domain with various twist angles, as shown in Figure 9d, which could provide rich research objects simultaneously. In recent years, the physics regarding twisted epitaxial graphene on SiC started to attract interest. Since 2012, the VHS has been systematically studied on the twisted multilayer epitaxial graphene  
Figure 9: Twisted epitaxial graphene on SiC.