Manipulation and Characterization of Aperiodical Graphene Structures Created in a Two-Dimensional Electron Gas
We demonstrate that Dirac fermions can be created and manipulated in a two-dimensional electron gas (2DEG). Using a cryogenic scanning tunneling microscope, we arranged coronene molecules one by one on a Cu(111) surface to construct artificial graphene nanoribbons with perfect zigzag (ZGNRs) or arm-chairedges and confirmed that new states localized along the edges emerge only in the ZGNRs. We further made and studied several typical defects, such as single vacancies, Stone-Wales defects, and dislocation lines, and found that all these defects introduce localized states at or near the Dirac point in the quasiparticle spectra. Our results confirm that artificial systems built on a 2DEG provide rigorous experimental verifications for several long-sought theoretical predications of aperiodic graphene structures.
A Planar square stack coupled inductor coils on silicon substrate has been fabricated using MEMS technology. The fabrication process utilized a simple, cost effective process technique as well as CMOS compatible resulting to a reproducible and good controlled process. The basic characteristics of the coupled inductors were discussed in wide range of operating frequency. The analysis results showed that the geometry of the inductor coil strongly affects the basic characteristics of the coils. The results of the study have promised a good prospect for the development of fully integrated planar magnetic field generator for sensing and actuating purposes.