Related papers: Moir\'e Kramers-Weyl Fermions from Structural Chir…
In this lecture for the Nobel symposium, we review previous research on a class of translational-invariant insulators without spin-orbit coupling. These may be realized in intrinsically spinless systems such as photonic crystals and…
The key feature of Weyl semimetals (WSM) is the presence of topologically protected Dirac cones in a 3D material. We consider the effect of restricting geometry on the spectrum of excitations in WSM using as a model a cylindrical WSM wire.…
We consider the existence of bulk chiral fermions around points of symmetry in the Brillouin zone of nonmagnetic 3D crystals with negligible spin-orbit interactions. We use group theory to show that this is possible, but only for a reduced…
The physics of phase transitions in low-dimensional systems has long been a subject of significant research interest. Long-range magnetic order in the strict two-dimensional limit, whose discovery circumvented the Mermin-Wagner theorem, has…
Weyl semimetals are well-known for hosting topologically protected linear band crossings, serving as the analog of the relativistic Weyl Fermions in the condensed matter context. Such analogy persists deeply, allowing the existence of the…
Motivated by the strong-correlation phenomenology observed near the superconducting phase in twisted bilayer WSe$_2$, we study multi-orbital $t$-$J$ models that are derived from different parameter regimes. The models contain effective…
We investigate the magnetic structures in a bilayer magnetic system with the locally inverted interlayer coupling region using Monte Carlo simulation. Stabilization of multiple magnetic structures including the magnetic skyrmion is possible…
The motion of a relativistic particle is linked to its spin by the Dirac equation. Remarkably, electrons in two-dimensional materials can mimic such Dirac particles but must always appear in pairs of opposite spin chirality. Using…
Materials that break time-reversal or inversion symmetry possess nondegenerate electronic bands, which can touch at so-called Weyl points. The spinor eigenstates in the vicinity of a Weyl point exhibit a well-defined chirality $\pm 1$.…
Layered van der Waals materials have risen as a powerful platform to engineer artificial competing states of matter. Here we show the emergence of multiferroic order in twisted chromium trihalide bilayers, an order fully driven by the…
Moir\'e superlattices in van der Waals structures can be used to control the electronic properties of the material and lead to emergent correlated and topological phenomena. Its first demonstration in van der Waals magnets exhibited…
Motivated by recent observation of the quantum spin Hall effect in monolayer germanene and twisted bilayer transition-metal-dichalcogenides (TMDs), we study the topological phases of moir\'e twisted bilayers with time-reversal symmetry and…
The dispersion relations of magnons in ferromagnetic pyrochlores with Dzyaloshinskii-Moriya interaction is shown to possess Weyl points, i.\,e., pairs of topological nontrivial crossings of two magnon branches with opposite topological…
Moir\'e superlattices in twisted bilayers enable profound reconstructions of the electronic bandstructure, giving rise to correlated states with remarkable tunability. Extending this paradigm to van der Waals magnets, twisting creates…
Triple point fermions are elusive electronic excitations that generalize Dirac and Weyl modes beyond the conventional high energy paradigm. Yet, finding real materials naturally hosting these excitations at the Fermi energy has remained…
Colossal magnetoresistance (CMR) is highly applicable in spintronic devices such as magnetic sensors, magnetic memory, and hard drives. Typically, CMR is found in Weyl semimetals characterized by perfect electron-hole symmetry or…
We show that the superconducivity in twisted graphene multilayers originates from a common feature, which is the strong valley symmetry breaking characteristic of these moir\'e systems at the magic angle. This leads to a breakdown of the…
Recent experimental realization of long sought Weyl fermions in non-magnetic crystals has greatly motivated condensed matter physicists to search for materials supporting Weyl fermions. Weyl fermions appear to be very promising for future…
We show that a class of compounds with $I$4/$mcm$ crystalline symmetry hosts three-dimensional semi-Dirac fermions. Unlike the known two-dimensional semi-Dirac points, the degeneracy of these three-dimensional semi-Dirac points is not…
The creation of moir\'e superlattices in twisted bilayers of two-dimensional crystals has been utilised to engineer quantum material properties in graphene and transition metal dichalcogenide (TMD) semiconductors. Here, we examine the…