Engineered electronic states in atomically precise artificial lattices and graphene nanoribbons

Abstract

The fabrication of atomically precise structures with designer electronic properties is one of the emerging topics in condensed matter physics. The required level of structural control can either be reached through atomic manipulation using the tip of a scanning tunneling microscope (STM) or by bottom-up chemical synthesis. In this review, we focus on recent progress in constructing novel, atomically precise artificial materials: artificial lattices built through atom manipulation and graphene nanoribbons (GNRs) realized by on-surface synthesis. We summarize the required theoretical background and the latest experiments on artificial lattices, topological states in onedimensional lattices, experiments on graphene nanoribbons and graphene nanoribbon heterostructures, and topological states in graphene nanoribbons. Finally, we conclude our review with an outlook to designer quantum materials with engineered electronic structure. 1 arXiv:1905.03328v4 [cond-mat.mtrl-sci]

Quantum Materials with Atomic Precision: Artificial Atoms in Solids: Ab Initio Design, Control, and Integration of Single Photon Emitters in Artificial Quantum Materials

“…Another promising approach is to pattern the surface of a high-bandgap material by STM lithography, already highly successful for P doping on silicon [83] . These and related techniques have also been explored in the context of other quantum phenomena [84][85][86] .…”

Morphological characterization and electronic properties of pristine and oxygen-exposed graphene nanoribbons on Ag(110)

“…10 The final product depends, indeed, on several factors, including the nature and geometry of the metallic substrate 11,20,21 and the structure of the precursor molecule. [10][11][12]17,[22][23][24] The choice of the proper compound is essential, since not all possible candidates are suitable and/or stable enough on the surface to allow for the dehydrogenation and C-C coupling processes leading to the formation of extended graphenic nanostructures. As an example, we mention the case of 1,5 dibromo-tetracene (DBT) and 1,6 di-bromo-pyrene (DBP), two halogenated aromatic hydrocarbons with similar molecular weight and different geometry: some of us produced ordered arrays of GNRs on Ag(110) from DBP polymerization, 12 while desorption prevails for DBT on the same substrate.…”

“…24 It is therefore possible to engineer GNRs (and C-based nanostructures in general) of desired final geometry, and thus tailored electronic properties, by selecting suitable precursor molecules. Energy gaps may then range from close to zero up to almost 3 eV 19,23,26,27 depending on the width of the nanoribbons and on whether they present armchair (AGNRs) or zigzag (ZGNRs) edge sites. For AGNRs, the band gap depends on the ribbon width and the nanostructures can be classified in three groups yielding large, medium or small bandgap, respectively.…”

“…For AGNRs, the band gap depends on the ribbon width and the nanostructures can be classified in three groups yielding large, medium or small bandgap, respectively. 23 On the contrary, ZGNRs have edge states associated with the zig-zag edge sites, 19 for which a nearly flat dispersion and a magnetic behaviour are predicted. 23 The determination of their electronic properties is therefore a pivotal task for the characterization of such nanostructures.…”

Engineering Metal-spxy Dirac Bands on the Oxidized SiC Surface

“…Design of 2D lattices. Given such an electronic scenario, based on the SSs induced by the metal s-orbital in the band gap of SiC, (M)Si 2 O 5 /SiC is an interesting and realistic semiconductor platform to design 2D lattices throughout the creation of metal vacancies on the surface [32,47]. Indeed, in a recent study, we explored the electronic properties of Archimedean lattice models based in a 2D s-orbital tight-binding model [15].…”