Related papers: Topological materials with extensive flat-band sur…
Flat-band periodic materials are characterized by a linear spectrum containing at least one band where the propagation constant remains nearly constant irrespective of the Bloch momentum across the Brillouin zone. These materials provide a…
As a half-metal is spin-polarized at its Fermi level by definition, it was conventionally thought to have little proximity effect to an s-wave superconductor. Here we show that, with interface spin-orbit coupling, $p_x +ip_y$…
Topological materials, such as topological insulators or semimetals, usually not only reveal the nontrivial properties of their electronic wavefunctions through the appearance of stable boundary modes, but also through very specific…
In a flat band superconductor, bosonic excitations can disperse while unpaired electrons are immobile. To study this strongly interacting system, we construct a family of multi-band Hubbard models with exact eta-pairing ground states in all…
We construct and characterize tight binding Hamiltonians which contain a completely flat topological band made of continuum lowest Landau level wavefunctions sampled on a lattice. We find an infinite family of such Hamiltonians, with simple…
We study the emergence of electronic non-trivial topological flat bands in time-periodically driven strained graphene within a tight binding approach based on the Floquet formalism. In particular, we focus on uniaxial spatially periodic…
Topological mechanical structures exhibit robust properties protected by topological invariants. In this letter, we study a family of deformed square lattices that display topologically protected zero-energy bulk modes analogous to the…
Weyl semimetals are examples of a new class of topological states of matter which are gapless in the bulk with protected surface states. Their low energy sector is characterized by massless chiral fermions which are robust against…
Topologically protected edge states have been extensively studied in systems characterized by the topological invariants in band gaps (also called line gaps). In this study, we unveil a whole new form of edge states that transcends the…
Topological materials rely on engineering global properties of their bulk energy bands called topological invariants. These invariants, usually defined over the entire Brillouin zone, are related to the existence of protected edge states.…
Based on first-principles calculations, we predict a half-metallic surface state in layered bulk insulator NaCoO2, with tunable surface hole concentration. The half-metallic surface has a single Fermi surface with a helical spin texture,…
We study the topologically non-trivial semi-metals by means of the 6-band Kane model. Existence of surface states is explicitly demonstrated by calculating the LDOS on the material surface. In the strain free condition, surface states are…
Surface states of a tight-binding model with nearest-neighbor hopping on a diamond lattice of finite thickness are investigated. We consider systems with (001), (110), and (111) surfaces. Even if the surface direction is fixed, there is…
Magnetic skyrmions are nanoscale spin configurations that can be efficiently created and manipulated. They hold great promises for next-generation spintronics applications. In parallel to these developments, the interplay of magnetism,…
We describe a three-dimensional crystalline topological insulator (TI) phase of matter that exhibits spontaneous polarization. This polarization results from the presence of (approximately) flat bands on the surface of such TIs. These flat…
We establish the topology of the spin-singlet superconducting states in the bare hyperhoneycomb lattice and derive analytically the full phase diagram using only symmetry and topology in combination with simple energy arguments. The phase…
We theoretically study the three-dimensional topological semimetals with nodal surfaces protected by crystalline symmetries. Different from the well-known nodal-point and nodal-line semimetals, in these materials, the conduction and valence…
In this letter, we report our systematic construction of the lattice Hamiltonian model of topological orders on open surfaces, with explicit boundary terms. We do this mainly for the Levin-Wen stringnet model. The full Hamiltonian in our…
At partial filling of a flat band, strong electronic interactions may favor gapped states harboring emergent topology with quantized Hall conductivity. Emergent topological states have been found in partially filled Landau levels and…
Flat-bands play a central role in the presence of correlated phases in Moir\'e and other modulated two dimensional systems. In this work, flat-bands are shown to exist in uniaxially periodic strained graphene. Such strain should be produced…