Related papers: Van Hove singularity-induced multiple magnetic tra…
We introduce a new type of van Hove singularity in two dimensions, where a saddle point in momentum space is changed from second-order to high-order. Correspondingly, the density of states near such ``high-order van Hove singularity'' is…
Recent experiments on Kagome metals AV$_3$Sb$_5$ (A=Cs,Rb,K) indicated spontaneous time-reversal symmetry breaking in the charge density wave state in the absence of static magnetization. The loop current order (LCO) is proposed as its…
We study unconventional superconductivity induced by weak repulsive interactions in 2D electronic systems at Van Hove singularity (VHS) where density of states is logarithmically divergent. We define two types of VHS. For systems at type-I…
Van Hove singularities (VHSs) in proximity to the Fermi level promote electronic interactions and generate diverse competing instabilities. It is also known that a nontrivial Berry phase derived from spin-orbit coupling (SOC) can introduce…
Recent experiments have observed correlated insulating and possible superconducting phases in twisted homobilayer transition metal dichalcogenides (TMDs). Besides the spin-valley locked moire bands due to the intrinsic Ising spin-orbit…
Altermagnetic (AM) fluctuations are a new class of collinear spin fluctuations whose role in mediating superconductivity faces a fundamental tension: their $\Gamma$-point peak favors intra-orbital spin-triplet pairing, while their spin…
We investigate a competition of tendencies towards ferromagnetic and incommensurate order in two-dimensional fermionic systems within functional renormalization group technique using temperature as a scale parameter. We assume that the…
Doped Mott insulators exhibit some of the most intriguing quantum phases of matter, including quantum spin-liquids, unconventional superconductors, and non-Fermi liquid metals. Such phases often arise when itinerant electrons are close to a…
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…
The properties displayed by graphene at van Hove singularities (VHS) have caught significant attention in recent years. The emergence of exotic quantum states at these singularities prompts investigations on their evolution within the realm…
Higher-order Van Hove singularities in strongly correlated electron systems provide a fertile ground for emergent electronic orders and superconductivity. This study investigates the interplay between magnetic fluctuations and…
We propose a new approach to the pseudogap problem in cuprates. Hole-doped cuprates display a broad plateau in the susceptibility centered near $(\pi,\pi)$. Competition between the softening of different $q$-modes on this plateau leads to…
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…
We introduce the photonic analogue of electronic Van Hove singularities (VHS) in artificial media (metamaterials) with hyperbolic dispersion. Unlike photonic and electronic crystals, the VHS in metamaterials is unrelated to the underlying…
We investigate the crossover from an ordinary van Hove singularity (OVHS) to a higher order van Hove singularity (HOVHS) in a model applicable to Bernal bilayer graphene and rhombohedral trilayer graphene in a displacement field. At small…
In quantum many-body systems, particularly, the ones with large near-EF density states, like flat bands or van Hove singularity (VHS), electron correlations often give rise to rich phase diagrams with multiple coexisting/competing orders…
Magnetically intercalated transition metal dichalcogenides are emerging as a rich platform for exploring exotic quantum states in van der Waals magnets. Among them, CoxTaS2 has attracted intense interest following the recent discovery of a…
We establish a unified, symmetry-driven framework that combines the alternating spin splitting of altermagnets with valley topology to realize and electrically interconvert helical and chiral topological phases within a single material…
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…
Altermagnetism (AM), the recently discovered third class of collinear magnetic order, is characterized by non-relativistic momentum-dependent spin-split electronic structure with compensated zero net magnetization. It can arise from the…