Related papers: Kohn-Luttinger superconductivity in graphene
We study the Hubbard model on the honeycomb lattice with nearest-neighbor hopping ($t>0$) and next-nearest-neighbor one ($t'<0$). When $t'<-t/6$, the single-particle spectrum is featured by the continuously distributed Van-Hove saddle…
Graphene has exhibited a wealth of fascinating properties, but is also known not to be a superconductor. Remarkably, we show that graphene can be made a conventional Bardeen-Cooper-Schrieffer superconductor by the combined effect of charge…
Vertical graphene heterostructures made up of graphene layers separated by BN spacers allow for novel ways of tuning the interactions between electrons. We study the possibility of electron pairing mediated by modified repulsive…
Recently Kawashima has reported that, when wetted with alkanes, several forms of graphite and single-layer graphene exhibit superconductor-like properties above room temperature under ambient pressure [AIP Adv. 2013, 3, 052132;…
The band structure of graphene exhibits van Hove singularities (VHS) at doping x=+- 1/8 away from the Dirac point. Near the VHS, interactions effects, enhanced due to the large density of states, can give rise to various many-body phases at…
Gapless superconductivity can arise when pairing occurs between fermion species with different Fermi surface sizes, provided there is a sufficiently large mismatch between Fermi surfaces and/or at sufficiently large coupling constant. In…
The superconducting upper critical field $H_{c2}(T)$ of a two dimensional BCS superconductor is calculated in the vicinity of a van-Hove singularity. The zero temperature upper critical field is strongly enhanced at weak coupling when the…
Recent angle-resolved photoemission (ARPES) experiments have indicated that the electronic dispersion in some of the cuprates possesses an extended saddle point near the Fermi level which gives rise to a density of states that diverges like…
We study the inter-valley scattering induced by the Coulomb repulsion as a purely electronic mechanism for the origin of superconductivity in few layers of graphene. The pairing is strongly favored by the presence of van Hove singularities…
In this thesis, I study a two-dimensional extended Hubbard model in the weak coupling limit. Quite generally, the electron gas is unstable towards a superconducting state even in the absence of phonons. However in the special case of a…
We consider possible superconducting instabilities in a two-dimensional Fermi system with short-ranged repulsive interactions between electrons. The possibility of an unusual superconducting paring due to the Kohn-Luttinger mechanism is…
Inhomogeneous superconductivity arises when the species participating in the pairing phenomenon have different Fermi surfaces with a large enough separation. In these conditions it could be more favorable for each of the pairing fermions to…
The moir\'e superlattice induced in graphene by the hexagonal boron nitride substrate modifies strongly the bandstructure of graphene, which manifests itself by the appearance of new Dirac points, accompanied by van Hove singularities. In…
We identify graphene as a system where chiral superconductivity can be realized. Chiral superconductivity involves a pairing gap that winds in phase around the Fermi surface, breaking time reversal symmetry. We consider a unique situation…
Motivated by the phenomenology of graphene moir\'e superlattices, we study a 2D model with strong tendencies towards both magnetism and triplet superconductivity. Individually, their respective order parameters, $\vec{N}$ and $\vec{d}$,…
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…
We study electronic ordering instabilities of twisted bilayer graphene with $n=2$ electrons per supercell, where correlated insulator state and superconductivity are recently observed. Motivated by the Fermi surface nesting and the…
Magic-angle twisted bilayer graphene exhibits quasi-flat low-energy bands with Van Hove singularities close to the Fermi level. These singularities play an important role in the exotic phenomena observed in this material, such as…
The effect of Coulomb interaction in an ensemble of Dirac fermions on the formation of superconducting pairing in monolayer and bilayer doped graphene is studied using the Kohn-Luttinger mechanism disregarding the Van der Waals potential of…
We report the observation of superconductivity in rhombohedral trilayer graphene electrostatically doped with holes. Superconductivity occurs in two distinct regions within the space of gate-tuned charge carrier density and applied electric…