Abstract
ABC-stacked epitaxial graphene domains for future quantum applications
In graphene, emergent properties such as superconductivity and ferroelectricity have been observed in ABC-stacked domains, typically obtained through exfoliation followed by precise mechanical twisting and alignment with the desired orientation. This process is challenging and non-scalable.
Here, we demonstrate that ABC-stacked graphene can be obtained using a scalable growth technique, namely, the thermal decomposition of silicon carbide. Using conductive atomic force microscopy, we identified distinct conductivity patterns in untwisted trilayer epitaxial graphene on silicon carbide. These patterns revealed the presence of ABA and ABC domains, matching the conductivity differences observed in twisted exfoliated graphene and those predicted by density functional theory. The size and geometry of the stacking domains depend on the interplay between strain, solitons crossing, and the shape of the three-layer regions. Furthermore, we showed that by controlling the strain of the graphene lattice, we can tune the dimension and geometry of moiré patterns. This study demonstrates the potential of the thermal decomposition method for producing ABA/ABC domains, paving the way for future quantum applications.
Biography
Martin Rejhon received his Doctoral Degree in Quantum Optics and Optoelectronics from Charles University, the Czech Republic, in 2019. He subsequently worked as a postdoctoral researcher in the Department of Chemical and Biomolecular Engineering at the Tandon School of Engineering, New York University, in the group of Prof. Elisa Riedo, where he investigated the nanomechanical properties of two-dimensional (2D) materials. His research focused particularly on pressure-induced phase transitions in 2D materials and their potential technological applications.
Since the beginning of 2023, he has been employed at the Institute of Physics, Charles University. His current research focuses on controlling the stacking order in epitaxial graphene layers grown on SiC substrates, hydrogen intercalation, and its influence on electronic properties.
Among the highlights of his scientific career is the award of a highly competitive Junior Star grant for excellent early-career researchers, with a funding volume of 1 million EUR, which enables him to explore in depth the control of stacking order between graphene layers and its future applications in optoelectronics.