Maciej.bazarnik

Author(s): Grigory Tarnopolsky, Alex Jura Kruchkov, and Ashvin Vishwanath

The angles at which flat bands emerge to produce superconductivity in twisted bilayer graphene are shown to be fundamentally connected to quantum Hall wave functions.

[Phys. Rev. Lett. 122, 106405] Published Fri Mar 15, 2019

Author(s): A. Sabitova, R. Temirov, and F. S. Tautz

A modified scheme of scanning tunneling spectroscopy data analysis has been used to reconstruct the band structure of a strongly dispersive two-dimensional unoccupied electronic state located at the commensurate interface between a monolayer of 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) a...

[Phys. Rev. B 98, 205429] Published Thu Nov 29, 2018

Two-dimensional tessellation by molecular tiles constructed from halogen–halogen and halogen–metal networks

Two-dimensional tessellation by molecular tiles constructed from halogen–halogen and halogen–metal networks, Published online: 19 November 2018; doi:10.1038/s41467-018-07323-6

Interconnecting porphines and graphene nanoribbons: Porphine homocoupling and covalent attachment of porphines to graphene nanoribbons under atomically well‐defined on‐surface conditions was investigated by bond‐resolved scanning tunneling and atomic force microscopy. The thermally induced reactions on Ag(111) afford distinct coupling motifs, the relative abundance of which is associated with stepwise reaction mechanisms.

Abstract

The templated synthesis of porphyrin‐based oligomers and heterosystems is of considerable interest for materials with tunable electronic gaps, photovoltaics, or sensing device elements. In this work, temperature‐induced dehydrogenative coupling between unsubstituted free‐base porphine units and their attachment to graphene nanoribbons on a well‐defined Ag(111) support are scrutinized by bond‐resolved scanning probe microscopy techniques. The detailed inspection of covalently fused porphine dimers obtained by in vacuo on‐surface synthesis clearly reveals atomistic details of coupling motifs, whereby also putative reaction intermediates are identified. Moreover, the covalent attachment of porphines at preferred locations of atomically precise armchair‐type graphene nanoribbons is demonstrated.

Up to speed: The extraordinary spatiotemporal resolution of high‐speed AFM permitted visualization of the seeded growth and self‐repair of supramolecular polymers in real time, and scanning‐probe AFM permitted the site‐specific manipulation and functionalization of a molecular self‐assembly (see picture). This combination of bottom‐up and top‐down approaches at the molecular level should enable the targeted synthesis of functional nanoarchitectures.

Abstract

Despite recent advances in mechanistic understanding and controlled‐synthesis methodologies regarding synthetic supramolecular assemblies, it has remained challenging to capture the molecular‐level phenomena in real time, thus hindering further progress in this research field. In this study, we applied high‐speed atomic‐force microscopy (AFM), which has extraordinary spatiotemporal resolution (1 nm and sub‐100 ms), to capture dynamic events occurring during synthetic molecular self‐assembly. High‐speed AFM permitted the visualization of unique dynamic behavior, such as seeded growth and self‐repair in real time. Furthermore, scanning‐probe AFM permitted the site‐specific manipulation and functionalization of a molecular self‐assembly. This powerful combination of bottom‐up and top‐down approaches at the molecular level should enable targeted syntheses of unprecedented functional nanoarchitectures.

Giant and anisotropic many-body spin–orbit tunability in a strongly correlated kagome magnet

Giant and anisotropic many-body spin–orbit tunability in a strongly correlated kagome magnet, Published online: 12 September 2018; doi:10.1038/s41586-018-0502-7

Author(s): Marina Pivetta, Stefano Rusponi, and Harald Brune

We show that the moiré pattern of graphene on Ir(111) acts as efficient template for the self-assembly of well-ordered superlattices of single rare-earth adatoms. Using Sm and Dy as representative of early and late lanthanides, we observe that the array quality is determined by the deposition temper...

[Phys. Rev. B 98, 115417] Published Mon Sep 10, 2018