Related papers: Van Hove Singularity and Lifshitz Transition in Th…
At very high doping levels the van Hove singularity in the $\pi^*$ band of graphene becomes occupied and exotic ground states possibly emerge, driven by many-body interactions. Employing a combination of ytterbium intercalation and…
Electronic instabilities at the crossing of the Fermi energy with a Van Hove singularity in the density of states often lead to new phases of matter such as superconductivity, magnetism or density waves. However, in most materials this…
We report on the interplay between a van Hove singularity and a charge density wave state in 2H-TaSe$_{2}$. We use angle-resolved photoemission spectroscopy to investigate changes in the Fermi surface of this material under surface doping…
We report on Hybrid-Monte-Carlo simulations at finite spin density of the $\pi$-band electrons in monolayer graphene with realistic inter-electron interactions. Unlike simulations at finite charge-carrier density, these are not affected by…
The electronic structure and phase stability of paramagnetic FeSe is computed by using a combination of ab initio methods for calculating band structure and dynamical mean-field theory. Our results reveal a topological change (Lifshitz…
Heavily doping graphene by intercalation can raise its Fermi level near an extended van Hove singularity, potentially inducing correlated electronic phases. Intercalation also modifies the band structure: dopants may hybridize with carbon…
Van-Hove (vH) singularities in the vicinity of the Fermi level facilitate the emergence of electronically mediated Fermi surface instabilities. This is because they provide a momentum-localized enhancement of density of states promoting…
In two-dimensional electronic lattices, changes in the topology of the Fermi surface (Lifshitz transitions) lead to Van Hove singularities characterized by a divergence in the electronic density of states. Van Hove singularities can enhance…
Extensive scanning tunnelling microscopy and spectroscopy experiments complemented by first principles and parameterized tight binding calculations provide a clear answer to the existence, origin and robustness of van Hove singularities…
Gold intercalation between the buffer layer and a graphene monolayer of epitaxial graphene on SiC(0001) leads to the formation of quasi free standing small aggregates of clusters. Angle Resolved Photoemission Spectroscopy measurements…
As the Fermi level and band structure of two-dimensional materials are readily tunable, they constitute an ideal platform for exploring Lifshitz transition, a change in the topology of a material's Fermi surface. Using tetralayer graphene…
Dispersionless energy bands are a peculiar property gathering increasing attention for the emergence of novel photonic, magnetic and electronic properties. Here we report the first observation of a graphene superstructure n-doped up to the…
Van Hove singularities (VHS's) in the density of states play an outstanding and diverse role for the electronic and thermodynamic properties of crystalline solids. At the critical point the Fermi surface connectivity changes and topological…
We report electric field-controlled modulation of the Fermi surface topology and explore its effects on the superconducting state in alternating-angle twisted quadrilayer graphene (TQG). The unique combination of flat and dispersive bands…
This study presents a method based on the total internal reflection and the phase-shifting interferometry for measuring the Van Hove singularities in strained graphene. A linearly polarized light passes through some quarter- and half-wave…
The nature of the coupling leading to superconductivity in layered materials such as high-Tc superconductors and graphite intercalation compounds (GICs) is still unresolved. In both systems, interactions of electrons with either phonons or…
Motivated by the pseudogap state of the cuprates, we introduce the concept of an "exceptional" van Hove singularity that appears when strong electron-electron interaction splits an otherwise simply connected Fermi surface into multiply…
We performed detailed studies of the current-voltage characteristics in graphene/MoS2/metal vertical field-effect transistors. Owing to its low density of states, the Fermi level in graphene is very sensitive to its carrier density and thus…
The Van Hove singularity (VHS) provides a paradigm for the study of the role of peaks in the density of states (dos) on electronic properties. More importantly, it appears to play a major role in the physics of the high-T_c superconductors,…
The essential properties of graphite-based 3D systems are thoroughly investigated by the first-principles method. Such materials cover a simple hexagonal graphite, a Bernal graphite, and the stage-1 to stage-4 Li/Li$^+$ graphite…