# Origin of Giant Rashba Effect in Graphene on Pt/SiC

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## Abstract

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## 1. Introduction

## 2. Materials and Methods

## 3. Results and Discussion

## 4. Conclusions

## Supplementary Materials

## Author Contributions

## Funding

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 1.**XPS spectra of the C 1s (

**a**) and Si 2p (

**b**) core levels measured for ZLG on SiC—bottom row, and after 1.5 Å Pt intercalation underneath ZLG on SiC—top row. The photon energy is 1486.6 eV.

**Figure 2.**Angle-resolved XPS spectra measured at emission angles of 0${}^{\circ}$ and 60${}^{\circ}$ relative to the surface normal for (

**a**)—C 1s, (

**b**)—Pt 4f and (

**c**)—Si 2p core levels, after Pt intercalation underneath ZLG on SiC. The photon energy is 1486.6 eV.

**Figure 3.**(

**a**,

**b**)—LEED patterns of the initial surface of $(6\sqrt{3}\times 6\sqrt{3})$R30° reconstruction of the SiC surface (zero-layer graphene) with a small amount of graphene monolayer and the surface after 1.5 Å Pt intercalation, E${}_{p}$ = 100 eV. (

**c**)—ARPES intensity maps of the surface after Pt intercalation measured along the $\overline{\Gamma \mathrm{K}}$ direction of the surface Brillouin zone and presented as the second derivative by energy. (

**d**,

**e**)—ARPES intensity maps of the initial surface and after Pt intercalation measured in the direction orthogonal to the $\overline{\Gamma \mathrm{K}}$. Solid red lines show the result of momentum distribution curves fitting with two Lorentzian peak functions. The enlarged view of the Dirac cone for the initial surface shown in the inset with inverted palette. (

**f**)—ARPES data from (

**e**) presented as the second derivative by energy to discern the main features more clearly. The photon energy is 40.8 eV (He II$\alpha $).

**Figure 4.**Spin-ARPES spectra (

**a**) with the spin polarizations (

**b**) of Gr/Pt/SiC(0001) system measured at ${k}_{1}$, ${k}_{2}$ and ${k}_{3}$ momenta in Figure 3c. In (

**a**), blue and red colors denote opposite sign projections of an electron spin vector, lying in-plane and directed perpendicular to the momentum. The photon energy is 40.8 eV (He II$\alpha $).

**Figure 5.**STM images for the system graphene/Pt/SiC after annealing at temperature T = 1100 °C. The image sizes and measurement parameters are as follows: (

**a**) 30 × 30 nm, V${}_{s}$ = −0.4 V, I${}_{t}$ = 0.5 nA, (

**b**) 11 × 11 nm, V${}_{s}$ = −0.5 V, I${}_{t}$ = 0.5 nA. A 2D FFT of the STM image is shown on the inset in panel (

**b**). (

**c**) 3D view of the image with 2D FFT filtering for graphene lattice visibility. The enlarged area is presented in the inset.

**Figure 6.**The model slab systems of Gr/Pt interface: (8 × 8) with flat graphene and Pt layer (

**a**), (8 × 8) with a large-scale graphene corrugation (

**b**) and (9 × 9) with graphene corrugation induced by Pt atom (

**c**). The corresponding DFT calculated unfolded bands near $\overline{\mathrm{K}}$ point along $\overline{\Gamma \mathrm{K}\mathrm{M}}$ direction of graphene Brillouin zone are shown on the right side. The symbol size and colour palette denote the Bloch spectral weight of carbon atoms for unfolded band structure.

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**MDPI and ACS Style**

Rybkina, A.A.; Gogina, A.A.; Tarasov, A.V.; Xin, Y.; Voroshnin, V.Y.; Pudikov, D.A.; Klimovskikh, I.I.; Petukhov, A.E.; Bokai, K.A.; Yuan, C.;
et al. Origin of Giant Rashba Effect in Graphene on Pt/SiC. *Symmetry* **2023**, *15*, 2052.
https://doi.org/10.3390/sym15112052

**AMA Style**

Rybkina AA, Gogina AA, Tarasov AV, Xin Y, Voroshnin VY, Pudikov DA, Klimovskikh II, Petukhov AE, Bokai KA, Yuan C,
et al. Origin of Giant Rashba Effect in Graphene on Pt/SiC. *Symmetry*. 2023; 15(11):2052.
https://doi.org/10.3390/sym15112052

**Chicago/Turabian Style**

Rybkina, Anna A., Alevtina A. Gogina, Artem V. Tarasov, Ye Xin, Vladimir Yu. Voroshnin, Dmitrii A. Pudikov, Ilya I. Klimovskikh, Anatoly E. Petukhov, Kirill A. Bokai, Chengxun Yuan,
and et al. 2023. "Origin of Giant Rashba Effect in Graphene on Pt/SiC" *Symmetry* 15, no. 11: 2052.
https://doi.org/10.3390/sym15112052