Publications (61)
Giant magnetic exchange coupling in rhombus-shaped nanographenes with zigzag periphery
Shantanu Mishra, Xuelin Yao, Qiang Chen +11
Nanographenes with zigzag edges are predicted to manifest non-trivial pi-magnetism resulting from the interplay of hybridization of localized frontier states and Coulomb repulsion…
Observation of the Ferromagnetic Kondo Effect
Elia Turco, Nils Krane, Hongyan Chen +5
The quest for quantum ground states beyond the conventional Fermi-liquid paradigm remains a central challenge in many-body physics. The ferromagnetic Kondo effect represents a part…
Ultimately-scaled electrodes for contacting individual atomically-precise graphene nanoribbons
Jian Zhang, Liu Qian, Gabriela Borin Barin +10
Bottom-up synthesized graphene nanoribbons (GNRs) are quantum materials that can be structured with atomic precision, providing unprecedented control over their physical properties…
On-surface synthesis of graphene nanoribbons with zigzag edge topology
Pascal Ruffieux, Shiyong Wang, Bo Yang +11
Graphene-based nanostructures exhibit a vast range of exciting electronic properties that are absent in extended graphene. For example, quantum confinement in carbon nanotubes and…
Electronic Band Dispersion of Graphene Nanoribbons via Fourier-Transformed Scanning Tunneling Spectroscopy
Hajo Söde, Leopold Talirz, Oliver Gröning +6
Atomically precise armchair graphene nanoribbons of width (7-AGNRs) are investigated by scanning tunneling spectroscopy (STS) on Au(111). The analysis of energy-dependent sta…
Electronic and Vibrational Properties of On-Surface Synthesized Gulf-Edged Chiral Graphene Nanoribbons
Xuanchen Li, Amogh Kinikar, Vikas Sharma +8
On-surface synthesis enables graphene nanoribbons (GNRs) with atomic precision, but the structural diversity of chiral GNRs remains constrained by the limited range of precursor ar…
The role of precursor coverage in the synthesis and substrate transfer of graphene nanoribbons
Rimah Darawish, Oliver Braun, Klaus Muellen +4
Graphene nanoribbons (GNRs) with atomically precise widths and edge topologies have well-defined band gaps that depend on ribbon dimensions, making them ideal for room-temperature…
Sensing a magnetic rare-earth surface alloy by proximity effect with an open-shell nanographene
Nicolò Bassi, Jan Wilhelm, Nils Krane +10
Open-shell nanographenes have attracted significant attention due to their structurally tunable spin ground state. While most characterization has been conducted on weakly-interact…
Band Gap of Atomically Precise Graphene Nanoribbons as a Function of Ribbon Length and Termination
Leopold Talirz, Hajo Söde, Shigeki Kawai +7
We study the band gap of finite armchair graphene nanoribbons (7-AGNRs) on Au(111) through scanning tunneling microscopy/spectroscopy combined with density functional theor…
Twisted bilayer zigzag-graphene nanoribbon junctions with tunable edge states
Dongfei Wang, De-Liang Bao, Qi Zheng +14
Stacking two-dimensional layered materials such as graphene and transitional metal dichalcogenides with nonzero interlayer twist angles has recently become attractive because of th…
On-surface synthesis of antiaromatic and open-shell indeno[2,1-b]fluorene polymers and their lateral fusion into porous ribbons
Marco Di Giovannantonio, Kristjan Eimre, Aliaksandr V. Yakutovich +8
Polycyclic hydrocarbons have received great attention due to their potential role in organic electronics and, for open-shell systems with unpaired electron densities, in spintronic…
Platinum contacts for 9-atom-wide armchair graphene nanoribbons
Chunwei Hsu, Michael Rohde, Gabriela Borin Barin +7
Creating a good contact between electrodes and graphene nanoribbons (GNRs) has been a longstanding challenge in searching for the next GNR-based nanoelectronics. This quest require…
On-surface synthesis of polyazulene with 2,6-connectivity
Qiang Sun, Ian Cheng-Yi Hou, Kristjan Eimre +4
Azulene, the smallest neutral nonalternant aromatic hydrocarbon, serves as not only a prototype for fundamental studies but also a versatile building block for functional materials…
On-Surface Hydrogen-Induced Covalent Coupling of Polycyclic Aromatic Hydrocarbons via a Superhydrogenated Intermediate
Carlos Sánchez-Sánchez, José Ignacio MartÃnez, Nerea Ruiz del Arbol +5
The activation and subsequent covalent coupling of polycyclic aromatic hydrocarbons (PAHs) are of great interest in fields like chemistry, energy, biology, or health, among others.…
Tailoring magnetism of nanographenes via tip-controlled dehydrogenation
Chenxiao Zhao, Qiang Huang, Leoš Valenta +10
Atomically precise graphene nanoflakes, called nanographenes, have emerged as a promising platform to realize carbon magnetism. Their ground state spin configuration can be anticip…
Optimized Graphene Electrodes for contacting Graphene Nanoribbons
Oliver Braun, Jan Overbeck, Maria El Abbassi +12
Atomically precise graphene nanoribbons are a promising emerging class of designer quantum materials with electronic properties that are tunable by chemical design. However, many c…
Step-Edge Passivation and Quantitative Raman Mapping of Transfer Quality in Aligned Graphene Nanoribbons
Dominik Lüthi, Rimah Darawish, Klaus Müllen +2
The transfer of aligned graphene nanoribbons from metallic growth surfaces to device-compatible platforms remains a central bottleneck for nanoribbon electronics. Here, we investig…
Coupled spin states in armchair graphene nanoribbons with asymmetric zigzag edge extensions
Qiang Sun, Xuelin Yao, Oliver Groning +6
Carbon-based magnetic structures promise significantly longer coherence times than traditional magnetic materials, which is of fundamental importance for spintronic applications. A…
Interfacial Coupling and Sparse Intercalation of 7-Atom-Wide Armchair Graphene Nanoribbons by N-Heterocyclic Carbene Monolayers
Dominik Lüthi, Dominik Lüthi, Lin Yang +6
Graphene nanoribbons (GNRs) synthesized on metal substrates experience electronic coupling and screening from the underlying surface, which, although often weak, can modify their o…
MoRe Electrodes with 10-nm Nanogaps for Electrical Contact to Atomically Precise Graphene Nanoribbons
Damian Bouwmeester, Talieh S. Ghiasi, Gabriela Borin Barin +4
Atomically precise graphene nanoribbons (GNRs) are predicted to exhibit exceptional edge-related properties, such as localized edge states, spin polarization, and half-metallicity.…
Conformational tuning of magnetic interactions in coupled nanographenes
Gonçalo Catarina, Elia Turco, Nils Krane +6
Phenalenyl (CH) is an open-shell spin- nanographene. Using scanning tunneling microscopy (STM) inelastic electron tunneling spectroscopy (IETS), covalently-bonded p…
Scaling and Statistics of Bottom-Up Synthesized Armchair Graphene Nanoribbon Transistors
Yuxuan Lin, Zafer Mutlu, Gabriela Borin Barin +8
Bottom-up assembled nanomaterials and nanostructures allow for the studies of rich and unprecedented quantum-related and mesoscopic transport phenomena. However, it can be difficul…
One-dimensional carbon nanostructures with periodic graphitic nitrogen substitution
Nicolò Bassi, Shantanu Mishra, Zheng Zhang +8
Heteroatom substitution is a powerful route to tune the chemical and electronic properties of carbon nanomaterials. In particular, replacement of an sp2 hybridized carbon atom in t…
Charge-carrier dynamics in single-wall carbon nanotube bundles: A time-domain study
Tobias Hertel, Roman Fasel, Gunnar Moos
We present a real-time investigation of ultrafast carrier dynamics in single-wall carbon nanotube bundles using femtosecond time-resolved photoelectron spectroscopy. The experiment…
On-surface synthesis and characterization of Teranthene and Hexanthene: Ultrashort graphene nanoribbons with mixed armchair and zigzag edges
Gabriela Borin Barin, Marco Di Giovannantonio, Thorsten G. Lohr +8
Graphene nanoribbons (GNRs) exhibit a broad range of physicochemical properties that critically depend on their width and edge topology. While the chemically stable GNRs with armch…
Giant edge state splitting at atomically precise zigzag edges
Shiyong Wang, Leopold Talirz, Carlo A. Pignedoli +4
Zigzag edges of graphene nanostructures host localized electronic states that are predicted to be spin-polarized. However, these edge states are highly susceptible to edge roughnes…
Gapless spin excitations in nanographene-based antiferromagnetic spin-1/2 Heisenberg chains
Chenxiao Zhao, Lin Yang, João C. G. Henriques +8
Haldane's seminal work established two fundamentally different types of excitation spectra for antiferromagnetic Heisenberg quantum spin chains: gapped excitations in integer-spin…
Collective All-Carbon Magnetism in Triangulene Dimers
Shantanu Mishra, Doreen Beyer, Kristjan Eimre +8
Triangular zigzag nanographenes, such as triangulene and its pi-extended homologues, have received widespread attention as organic nanomagnets for molecular spintronics, and may se…
Atomic-scale imaging of graphene nanoribbons on graphene after polymer-free substrate transfer
Amogh Kinikar, Feifei Xiang, Lucia Palomino Ruiz +12
On-surface synthesis enables the fabrication of atomically precise graphene nanoribbons (GNRs) with properties defined by their shape and edge topology. While this bottom-up approa…
Optimized Synthesis and Device Integration of Long 17-Atom-Wide Armchair Graphene Nanoribbons
Jeong Ha Hwang, Nicolò Bassi, Mayada Fadel +15
Seventeen-carbon-atom-wide armchair graphene nanoribbons (17-AGNRs) are promising candidates for high-performance electronic devices due to their narrow electronic bandgap. Atomic…
Tunable quantum dots from atomically precise graphene nanoribbons using a multi-gate architecture
Jian Zhang, Oliver Braun, Gabriela Borin Barin +14
Atomically precise graphene nanoribbons (GNRs) are increasingly attracting interest due to their largely modifiable electronic properties, which can be tailored by controlling thei…
Observation of fractional edge excitations in nanographene spin chains
Shantanu Mishra, Goncalo Catarina, Fupeng Wu +9
Fractionalization is a phenomenon in which strong interactions in a quantum system drive the emergence of excitations with quantum numbers that are absent in the building blocks. O…
Probing optical excitations in chevron-like armchair graphene nanoribbons
Richard Denk, Alberto Lodi-Rizzini, Shudong Wang +15
The bottom-up fabrication graphene nanoribbons (GNRs) has opened new opportunities to specifically control their electronic and optical properties by precisely controlling their at…
Learning Inhomogeneous Heisenberg Hamiltonians in Nanographene Spin Chains
Greta Lupi, Saketh Ravuri, Chenxiao Zhao +9
Inferring microscopic Hamiltonians from experimental data is a central challenge in quantum materials and quantum simulation. In low-dimensional spin systems, exchange interactions…
Tunable topological phases in nanographene-based spin-1/2 alternating-exchange Heisenberg chains
Chenxiao Zhao, Gonçalo Catarina, Jin-Jiang Zhang +8
Unlocking the potential of topological order within many-body spin systems has long been a central pursuit in the realm of quantum materials. Despite extensive efforts, the quest f…
Superlubricity of Graphene Nanoribbons on Gold Surfaces
Shigeki Kawai, Andrea Benassi, Enrico Gnecco +9
The state of vanishing friction known as superlubricity has important applications for energy saving and increasing the lifetime of devices. Superlubricity detected with atomic for…
Advancing single-atom catalysts: engineered metal-organic platforms on surfaces
Amogh Kinikar, Xiushang Xu, Takatsugu Onishi +10
Recent advances in nanomaterials have pushed the boundaries of nanoscale fabrication to the limit of single atoms (SAs), particularly in heterogeneous catalysis. Single atom cataly…
Short-Channel Field Effect Transistors with 9-Atom and 13-Atom wide Graphene Nanoribbons
Juan Pablo Llinas, Andrew Fairbrother, Gabriela Borin Barin +21
Bottom-up synthesized GNRs and GNR heterostructures have promising electronic properties for high performance field effect transistors (FETs) and ultra-low power devices such as tu…
Stable ferromagnetism and doping induced half-metallicity in asymmetric graphene nanoribbons
Donat J. Adams, Oliver Gröning, Carlo A. Pignedoli +3
We propose a class of graphene nanoribbons showing strong intrinsic ferromagnetic behavior due to their asymmetry. Such ribbons are based on a zig-zag edged backbone surmounted by…
Edge Disorder in Bottom-Up Zigzag Graphene Nanoribbons: Implications for Magnetism and Quantum Electronic Transport
Michele Pizzochero, Gabriela Borin Barin, KristiÄns ÄerÅeviÄs +4
We unveil the nature of the structural disorder in bottom-up zigzag graphene nanoribbons along with its effect on the magnetism and electronic transport on the basis of scanning pr…
Quantum Electronic Transport Across "Bite" Defects in Graphene Nanoribbons
Michele Pizzochero, KristiÄns ÄerÅeviÄs, Gabriela Borin Barin +4
On-surface synthesis has recently emerged as an effective route towards the atomically precise fabrication of graphene nanoribbons of controlled topologies and widths. However, whe…
Quantifying Alignment and Quality of Graphene Nanoribbons: A Polarized Raman Spectroscopy Approach
Rimah Darawish, Jan Overbeck, Klaus Müllen +4
Graphene nanoribbons (GNRs) are atomically precise stripes of graphene with tunable electronic properties, making them promising for room-temperature switching applications like fi…
Anisotropy of Quasiparticle Lifetimes and the Role of Disorder for Ultrafast Electron Dynamics in Graphite
Gunnar Moos, Cornelius Gahl, Roman Fasel +2
Femtosecond time-resolved photoemission of photoexcited electrons in highly oriented pyrolytic graphite (HOPG) provides strong evidence for anisotropies of quasiparticle (QP) lifet…
Engineering of robust topological quantum phases in graphene nanoribbons
Oliver Gröning, Shiyong Wang, Xuelin Yao +10
Here we present a flexible strategy to realize robust nanomaterials exhibiting valence electronic structures whose fundamental physics is described by the SSH-Hamiltonian. These so…
Electronic decoupling and hole-doping of graphene nanoribbons on metal substrates by chloride intercalation
Amogh Kinikar, Thorsten G. Englmann, Marco Di Giovannantonio +14
Atomically precise graphene nanoribbons (GNRs) have a wide range of electronic properties that depend sensitively on their chemical structure. Several types of GNRs have been synth…
Demonstrating Kondo behavior by temperature-dependent scanning tunneling spectroscopy
Elia Turco, Markus Aapro, Somesh C. Ganguli +9
The Kondo effect describes the scattering of conduction electrons by magnetic impurities, manifesting as an electronic resonance at the Fermi energy with a distinctive temperature…
Growth optimization and device integration of narrow-bandgap graphene nanoribbons
Gabriela Borin Barin, Qiang Sun, Marco Di Giovannantonio +26
The electronic, optical and magnetic properties of graphene nanoribbons (GNRs) can be engineered by controlling their edge structure and width with atomic precision through bottom-…
Synthesis and characterization of super-nonazethrene
Elia Turco, Shantanu Mishra, Jason Melidonie +6
Beginning with the early work of Clar et al. in 1955, zethrenes and their laterally-extended homologues, super-zethrenes, have been intensively studied in the solution phase, and a…
Vibrational excitations in magnetic triangular nanographenes
Nils Krane, Elia Turco, Annika Bernhardt +3
Inelastic electron tunneling spectroscopy (IETS) is a powerful measurement technique often used in scanning tunneling spectroscopy to probe excited states of various nanostructures…
On determining the energy dispersion of spin excitations with scanning tunneling spectroscopy
J. C. G. Henriques, Chenxiao Zhao, G. Catarina +3
Conventional methods to measure the dispersion relations of collective spin excitations involve probing bulk samples with particles such as neutrons, photons or electrons, which ca…
Length-independent quantum transport through topological band states of graphene nanoribbons
Song Jiang, Fabrice Scheurer, Qiang Sun +7
Atomically precise graphene nanoribbons (GNRs) have emerged as promising candidates for nanoelectronic applications due to their widely tunable energy band gaps resulting from late…
O adsorption and incipient oxidation of the Mg(0001) surface
Elsebeth Schroder, Roman Fasel, Adam Kiejna
First principles density functional calculations are used to study the early oxidation stages of the Mg(0001) surface for oxygen coverages 1/16 <= Theta <= 3 monolayers. It is foun…
Structure-dependent electrical properties of graphene nanoribbon devices with graphene electrodes
Leonardo Martini, Zongping Chen, Neeraj Mishra +9
Graphene nanoribbons (GNRs) are a novel and intriguing class of materials in the field of nanoelectronics, since their properties, solely defined by their width and edge type, are…
Optimized substrates and measurement approaches for Raman spectroscopy of graphene nanoribbons
Jan Overbeck, Gabriela Borin Barin, Colin Daniels +13
The on-surface synthesis of graphene nanoribbons (GNRs) allows for the fabrication of atomically precise narrow GNRs. Despite their exceptional properties which can be tuned by rib…
Substrate transfer and ex situ characterization of on-surface synthesized graphene nanoribbons
Gabriela Borin Barin, Andrew Fairbrother, Lukas Rotach +13
Recent progress in the on-surface synthesis of graphene nanoribbons (GNRs) has given access to atomically precise narrow GNRs with tunable electronic band gaps that makes them exce…
Direct observation of the magnetic ground state of the two smallest triangular nanographenes
Elia Turco, Annika Bernhardt, Nils Krane +4
Fusion of three benzene rings in a triangular fashion gives rise to the smallest open-shell graphene fragment, the phenalenyl radical, whose -extension leads to an entire famil…
Engineering Ferrimagnetic Interactions in Molecular Quantum Systems
Elia Turco, Fupeng Wu, Annika Bernhardt +6
Achieving long-range ferrimagnetic order in purely organic systems remains a major challenge in molecular magnetism. Here we report the synthesis and characterization of heterospin…
Charge State-Dependent Symmetry Breaking of Atomic Defects in Transition Metal Dichalcogenides
Feifei Xiang, Lysander Huberich, Preston A. Vargas +11
The functionality of atomic quantum emitters is intrinsically linked to their host lattice coordination. Structural distortions that spontaneously break the lattice symmetry strong…
Controlled quantum dot formation in atomically engineered graphene nanoribbons field-effect transistors
Maria El Abbassi, Mickael Perrin, Gabriela Borin Barin +12
Graphene nanoribbons (GNRs) have attracted a strong interest from researchers worldwide, as they constitute an emerging class of quantum-designed materials. The major challenges to…
A Universal Length-Dependent Vibrational Mode in Graphene Nanoribbons
Jan Overbeck, Gabriela Borin Barin, Colin Daniels +13
Graphene nanoribbons (GNRs) have attracted considerable interest as their atomically tunable structure makes them promising candidates for future electronic devices. However, obtai…
Magnetic Excitations in Ferromagnetically Coupled Spin-1 Nanographenes
Elia Turco, Fupeng Wu, Gonçalo Catarina +5
In the quest for high-spin building blocks to form covalently bonded 1D or 2D materials with controlled magnetic interactions, -electron magnetism provides an ideal framework t…